A warrior must be handy, and I must use insanely bad puns for these title breaks.
Gloves are, like legs, an armor slot where a trip to the AH can serve you well. The Felsteel Gloves are waiting to be your out of the box tanking option at 70. Like all of the Felsteel set, they're a solid no frills option for a tank needing to cap his defense and can be socketed for whatever you feel deficient in. They won't break any hearts, but they do the job and a newly 70 tank can sigh in relief that he has a reliable option here.
Up and coming Scryer tanks miss out on the really rather nice tanking BP the Aldor get (holy defense, Batman!) but they do benefit in terms of gloves, as they get the Gauntlets of the Chosen. Yeah, okay, I'd rather have the BP too. Lower armor and stam than the Felsteels and no sockets vs. some agility and 10 defense rating doesn't seem like much of a trade off. I'd almost rather have these green gloves than the Scryer ones.
If you're putting together a SBV set (and why wouldn't you?) then look to Thatia's Self-Correcting Gauntlets. Not only are they part of the Green Wrath set of blue 70 tanking gear (and are thus awesome) but they have a hearty whack of SBV on them, and we all love that. Enchanted with threat these could be part of a block set for a long time. If you're looking for solid, middle of the road tanking gloves there's always the Gauntlets of the Bold, which frankly are more off-tank than tank in my opinion. Finally, if you're running heroic Botanica (perhaps for the rep to gain Crest of the Sha'tar) then don't ignore the Gauntlets of Dissention. They lack the sockets but are otherwise Bold on steroids, making them ideal offtanking gloves.
Boot camp! God, this one's even worse than the last one.
Okay, to get it out of the way: if you have the gold to get Red Havoc Boots crafted, just do that and skip this part. You'll wear them forever, well into BT/Hyjal. They're awesome. (Note: they're also BoP. I'm a dumbass. I have the plans to make them, just never bothered to.)
Assuming you're not going to do that, there are still several options available to you.
Okay, so maybe not several. Boots are just as bad as shoulders in terms of pure tanking before Karazhan. So bad, in fact, that I'm going to mention a Karazhan drop in here, as it can drop off of any mob in the instance: the Boots of Elusion. Some tanks never see them, some get them off of the first pull in the place. They're excellent dodge boots if you see them.
I wanted to go into Karazhan wearing the Boots of the Colossus. Sadly, they never dropped for my human. Or my tauren. Or my draenei. I would have loved to have two sockets, defense, and good solid tanking stats on my feet, but it was not to be. I made do with the Sha'tari Wrought Greaves until I could get the Flesh Beast's Metal Greaves instead. Both are quest drops, but the Greaves have nice stats for a fledgling 70 tank. The Sha'tari were just easier to get the quest done on, for whatever reason. I could just be backwards that way. And if you don't get those for some reason you could always fall back on the Ironsole Clompers, which are decent considering they drop in the first instance you'll run in Outland.
Finally, for offtanking and/or if you like threat, there's the Eaglecrest Warboots. Slightly harder to get but if you're grinding Honor Hold/Thrallmar rep anyway, give heroic Blood Furnace a shot and see if these drop for you.
Heading up the attack
Helmets for the tank preparing to go to Karazhan are a bit easier than, say, shoulders or boots.
Since I left them out and the uproar in the comments was extraordinary, here are the tanking goggles you can make as a level 62 engineer: Tankatronic Goggles. If you are an engineer, there you go, you won't even need to roll on T4 if you don't want to. They have a meta gem, solid defense, good stats overall, you won't find better. Now, if like me, you are not an engineer, there are other options.
There's two crafted helms to consider first: the Helm of the Stalwart Defender for those of us who have money or are blacksmiths, and the Felsteel Helm for those of us who are on a budget or are blacksmiths on a budget. The Felsteel is, like the rest of the set, solid, slightly unremarkable, and will do the job. Three sockets (and two of them blue, no less) give you a nice amount of customization. The Helm of the Stalwart Defender has higher base stamina and armor, worse socket colors (but they can be ignored), less defense but added resilience meaning that it will contribute towards reducing your incoming critical hits. Honestly, while the epic is probably a better hat all around, I wouldn't make one. But it exists and is a solid tanking hat, so I figured I should mention it here.
Badges will provide the Faceguard of Determination. This helm, as well as the Warhelm of the Bold and the Myrmidon's Headdress just got a big boost in the recent patch, thanks to the Eternal Earthstorm Diamond. Tanking hats with meta gem sockets are to be prized thanks to that lovely raw SBV boost. Say you have 400 SBV before you put that gem in. Now you have 440. That's a massive boost to your block value from one gem, and it scales as you get more block value. 500 SBV before the gem? Now it's 550. This directly translates to Shield Slam threat and it is not to be underestimated for a threat set. If you have one of these three hats with this meta gem in it you will probably keep it until you get Tier 4, just for a threat set.
Finally, this is BoE now. No, I've never seen it on the AH either, but you never know. Perhaps it will end up in a nearby AH. It is undeniable a solid tanking hat, well, it only belongs on a pre-Kara list because it is BoE, Doomwalker is not a pre-Kara boss.
Finally, I would be remiss if I didn't mention a green, right? It is a nice green, however, and if you're doing Netherwing dailies and don't have a tanking hat, look! SBV on a hat! Not that common. I'd still say the other hats listed here are far superior, but for a non-meta helmet this is a good choice for a threat set.
Belts can be another tough slot to armor up. So tough, in fact, that I ended up wearing the Girdle of the Lost Vindicator after every other slot in my inventory was epic. You're thinking "Why didn't you just get the Sha'tari Vindicator's Waistband" right now, and I don't blame you. I mean, I needed to get my arcatraz key anyway, right? Well, the problem was simple. No one wanted to run Botanica. I mean, no one. The one Botanica run I managed to get, I forgot to loot Warp Splinter. So yes, I was a dumbass wearing a green belt through his own fault for a very long time. My tauren had a better belt, my shamans all had their Arc keys, and I lost track of how many Mechanar runs I did but never, ever again did I go back to Bot. It's really rather astonishing and painful.
Basically, this entire belt section is a list of items that never dropped for me. So we can all point and laugh as I mention the Girdle of the Immovable, with its sockets and Shield Block rating. We can titter at the Lion's Heart Girdle, with its solid offtanking stats, because all I ever saw drop was the leather belt. And we can wonder if I saved my badges for the Iron-Tusk Girdle. I didn't, because this dropped the day before I would have had enough badges for it. Since Moroes is the second boss in Kara, I figure it's fair to mention that belt, but don't expect it to drop, as I'd given up on it before he finally coughed it up. I was tanking Prince in that green.
What cloak for your aspiring tank? The short answer is, as always, whatever drops first. But we'll go over the basics. There are basically four blue cloaks you should consider and a nice (very nice, in fact) badge cloak for a reasonable price as well.
First up is my favorite cloak, which I still wear in Hyjal from time to time: the Devilshark Cape. This is a cape with defense, stamina, dodge and shield block value. Seriously, it's astonishing. Even when you have epic cloaks that generally outperform it for mitigation or avoidance you'll keep it around for threat sets. It's quite simply the best blue warrior tanking cape in the game. It provides stats towards uncrittability and threat as well as stam. Farm Warlord Kalithresh non-stop until this drops, and amazingly, you can run it multiple times in a day as this cape isn't even a heroic drop.
If you need more defense the Burnoose of Shifting Ages is comparable, if not quite as good. More armor but less stam, equivalent SBV but no dodge, slightly more defense. It's a good warrior cape, certainly, and you'll be running Black Morass for Keepers of Time rep, and it is a very nice cloak, but it's not as good.
If you just want to hit the AH and start tanking, find the Cloak of Eternity. It's the Felsteel of cloaks, basically.
Finally, if you're running heroics for the other epic drops on this list, you might want to consider Slikk's Cloak of Placation. At 33 badges it's very affordable, and it has very solid avoidance stats plus a nice 37 stamina.
By now we've covered more or less every armor slot for a tanking warrior (shields, necklaces, bracers, rings, trinkets, chestplates, shoulders, legs, belts, boots, gloves and capes) which leaves one slot for the aspiring tank.
Weapons are of course very important for the tank. First we'll list the non-epic options before Karazhan, and then move on to epics.
Frankly, if you're tanking in Kara with a Crystalline Khopesh, don't. It's decent for getting through the 70 instances you need to get other gear, but look to replace it. A rewarding quest line in Shadowmoon Valley will gain you Grom'tor's Charge. This is an excellent, all around tanking weapon and it rewards an orc warrior with racial expertise bonuses as well. You can use this to run heroics for the chance to get the Truncheon of Five Hells (yay for hit rating!) in Heroic Ramparts or the Warp-Storm Warblade (did I say hooray for hit rating?) in Heroic Mana Tombs. However, if you're grinding SSO rep anyway, you'll probably at least want to look at Inuuro's Blade from revered SSO. For a human warrior this probably beats out any other rare weapon on this list, as it has hit, defense and expertise (plus the human racial) all in one package along with solid stamina. I've been reminded in the comments to mention Terrok's Nightmace. It does have solid tanking stats and the slow (relatively slow, anyway) speed means slightly bigger Devastate hits, and the expertise combined with the human racial makes it a serious contender for a human tank.
Horde, especially orcs, will probably upgrade to Warbringer as soon as they have exalted with Thrallmar. Alliance, especially those human folks, will likewise consider Honor's Call as their next weapon of choice once they have Honor Hold exalted. Both of these weapons are fine choices, of course. and I would have settled for either had I not gone mad and run Mechanar over and over and over again until The Sun Eater finally dropped. The Sun Eater is probably the best avoidance tanking weapon you can get before Kara, and is good enough to keep tanking through the 25 mans until an upgrade drops there.
And that seems like the end of our series on gearing a prot warrior for Karazhan, because it is. However, we're not out of the tower yet. We've yet to cover dps options for warriors. Next week, arms and fury wars get ready to step into the fray.