I know that sounds like a bit of a copout, but it is true. You can pretty much level straight to 70 and even 80 without ever touching a dungeon or learning a profession and do just fine. That said, there are certainly advantages to delving into dungeons or putting your Gnomish Army Knife to actual use. Let's take a look.
If you check out our Death Knight Profession column from a few weeks ago, you'll notice it's mostly geared toward the value of professions at level 80, but there are some minor reflections on the usefulness of various professions for leveling up in there too. So after that, the question remains: If you choose to go level up your professions to Outland level before you actually hit Outland, what should you grab?
As far as the quick and dirty lowdown goes, If you're looking for a useful leveling up skill, your best bet is probably Blacksmithing, since it will allow you to make decent armor upgrades throughout the 70s and 80s, and gives you the best access to good, easy to get tanking gear should you decided to start tanking before your max level. On the other hand, Blacksmithing can be annoying to level too. You'll be making a whole hell of a lot of Mithril Spurs, assuming you can even get your hands on the recipe drop.
The other option then, might be just to take a combination of gathering skills. Skinning/Mining is the old standby, since it allows you to track ore while skinning any beasts you kill, and it works out great for getting that Blacksmithing armor as well. Since most of the armor you'll want is BoE, you'll just be able to mine the ore yourself and find some sucker who actually leveled Blacksmithing to combine it for you. And anything you don't use, you can sell on the AH for flying funds, which is especially useful if your old character was poor.
Again, though, you can get to 80 without professions just fine, and it will probably be faster. But if you have your heart set on leveling your professions, check back issues of our own Insider Trader column or the official WoW Professions forums for some good trade skill leveling guides.
Do Dungeons have some decent gear upgrades? Yeah, sure. Do you absolutely need them to level up? Again, not especially. You can head straight to Northrend in your DK starting zone gear and do fine. In addition, it can sometimes waste more time standing around Honor Hold trying to find a Hellfire Ramparts group when you could just be in Zangarmarsh killing Hydra. That said, the quests can be decent experience, and you can get an upgrade or two. With that in mind, let's loot at the loot possibilities for a few dungeons.
Hellfire Ramparts: The Hellreaver here is a very respectable upgrade to your Greatsword, and should last you nicely til a honed voidaxe from Nagrand. The other drops here consist of very, very slight upgrades or side-grades. The Garrote-String Necklace will give you a slight AP upgrade from the Bladed Ebon Amulet, and critical strike rating in place of hit rating. The Ironsole Clompers should be decent for tanking if you want to do some Outland tanking. The Tenacious Defender will technically edge out The Plaguebringer's Girdle if you stick the right gems into it, but honestly, I'd save my gold for other things unless you have a cheap or free source for the gems.
Blood Furnace: The Warsong Howling Axe is another quick weapon upgrade from your quest weapon here. Ironblade Gauntlets are also a very definite upgrade in stats over Bloodbane's Gauntlets of Command, and the Pendant of Battle Lust provides a bit of (melee-only) critical strike rating to arguably nudge it past the Bladed Ebon Amulet in the neck department. I honestly probably wouldn't bother wearing the Perfectly Balanced Cape quest reward from here, though. All it does is switch the critical strike rating on your Death Knight quest reward cape with agilty, which does not affect the crit rating of spell-like abilities like Death Coil. It also uses straight attack power instead of strength, which does technically deprive you of a slight bit of parry rating.
The Slave Pens: This dungeon is a little more sparse for Death Knights. The Runed Fungalcap and the Bogstrok Scale Cloak are both worth looking out for for a beginning tank Death Knight, though. You might also get the Unscarred Breastplate off Quagmirran, a definite upgrade from the Saronite War Plate as long as you can spare the gold for a few gems. Again, don't be afraid to just pass and save your money for later expenses though.
The Underbog: The Hatebringer continues the tradition of good 2-hand weapon upgrades, although you'll have to visit a weapons trainer to learn 2-handed maces first. Greaves of the Iron Guardian make a nice upgrade to Engraved Saronite Legplates if you can spare a gem or two, and Pauldrons of Brute Force can be helpful to beginning tank Death Knights and will even prove a DPS upgrade if you add some gems to the slots.
But Do You Need This?
At the same time as I mention these dungeons, I feel I should reiterate that they can be as much stumbling blocks as helpers on the road to Northrend. If you're running the same dungeon over and over for a certain drop, you may very well be delaying your leveling. If you're spending all your gold on gems to socket all your dungeon gear, you may find your bank account sadly empty when it comes time to buy flight, epic flight, cold weather flying, or even just new skills. It may be worth it to run a dungeon or two if you have a group waiting, but don't get hung up on it.
Once you've read last week's column and gotten some insight on your leveling strategy, and used this article to help you decide whether to level a profession before you level to 70 and which dungeons to run on the way up, you should be good to go to speed up the levels and catch a boat to Northrend. We'll see you on the docks!