I have to tell you up front that joining a guild, especially a raiding guild, purely based on your relationship to an existing member is one of the toughest situations you can walk into. My guild is pretty lenient on these kinds of invites. As long as the person doesn't cause a stir in guild chat or run around the server pissing everyone off, we're happy to accommodate our member's real-life friends. But as officers we're not going to trust you to pull your weight in a raid until you prove to us you can.
The first thing we're going to do to determine whether you're raid-worthy is look at your Armory profile for your gear and your reputations. If we see someone in greens who isn't attuned to Heroics, we're going to assume that person is a casual player who probably doesn't understand what raiding is all about. Being keyed for Karazhan is a good start, but it hardly tells us that you deserve to be there. At this point, you're just "so-and-so's friend," whose presence we tolerate as a favor to him or her.
It's tough to gear up and get that reputation, however, when you can't get into groups to run anything. So the first thing you have to do is prove yourself to a few of the regular guild members. That means volunteering your time and/or gold to help people out. Run some lowbie alts through Scarlet Monastery. Help someone kill a fel reaver for their Shattered Halls key. Donate some Super Mana Potions to the healers heading into Gruul's Lair. When people see that you're trying to be a team player, they're much more likely to extend an invite when it's time to put together a 5-man team. Once you get in on some runs and people see that you have a clue, word will spread that you're a decent player to bring along. And that word will eventually trickle up to the officers -- trust me on this. You're on your way to being noticed.
Still, it's tough sometimes these days to get non-Heroic runs going. Fortunately you can gear up pretty well at level 70 just from BOE items and quests. There are plenty of soloable "Group" quests out there with pretty nice rewards that are comparable to what drops in Shadow Labyrinth or Arcatraz. Being a hunter makes it even easier. Just find every single-target elite quest you can and kite all those big nasties to the closest town. Bonus points for killing the lazy NPC who gave you that quest in the first place!
Once you have some decent gear, show your dedication to the cause by pimping it out. Get the best enchants, armor kits, and gems you can reasonably afford. Sure, you'll probably replace all this gear in a few weeks, but not if you never get into a raid.
In the meantime, be active (but not hyper) in guild chat and on your guild's Web site. Keep an upbeat attitude.
Most importantly, ask advice from your class leader about your spec, your shot rotation, etc. When your CL sees that you're taking your class seriously, they'll start to think that maybe you're more than just "so-and-so's friend." Your CL is really the key to your raid eligibility. In my guild, when we're putting a run together, we look at who's available, and the raid leader will often ask the class leaders for suggestions. If you've been diligent, your name will come up in this context as someone to try out during a farming run. Now you're in, and it's time to show what you can do!
Before the raid, make sure you've read up on all the bosses you'll be facing. Test your connection to the voice-chat server so you don't have to fiddle with it when the raid is ready to start. Bring more consumables than you could ever possibly need. Asking someone to "borrow a few bandages" is a quick way to make sure they don't invite you next time. Be there on time without asking for a summon. Even better, be there early to help summon others.
During your first raid, it's easy to get nervous or excited and make stupid mistakes. Make sure you're listening carefully to instructions, and ask your CL (or someone with the same role) if you get confused. Only ask the raid leader as a last resort -- he or she probably has enough on their plate at any given moment. Don't spam the raid channel or the voice-chat server with your questions and comments. Keep it in whispers or your class's chat channel, if your guild uses them. Someone will be watching you, whether using an add-on or a combat log compiler, so don't slack off, even during trash pulls. If you do happen to make a fatal error, own up to it and apologize. Explain what happened. Your officers will be impressed that you're willing to admit a mistake and able to figure out what went wrong. We've all been there, and it's better to step up and be an adult about it than try to pass it off as someone else's fault. Just don't make the same mistake twice.
The ideal situation is that no one really notices you during the run, but they see at the end that you've put up solid numbers, kept good crowd control on your assignments, and didn't unduly bother anyone. Standing out in a raid situation usually means you've done something terribly wrong.
When all is said and done, officers respect those who contribute and those willing to learn how to contribute. So best of luck to all you peons out there -- and hats off to my own! Without you guys, none of us could have a guild at all . . .
Send Scott your guild-related questions, conundrums, ideas, and suggestions at firstname.lastname@example.org. You may find your question the subject of next week's Officers' Quarters!