Firstly, don't be afraid to raid.
I was a noob raider until I joined PCG. Now I can't get enough of raiding
As Aphaeas has given you some advice, I'll just add - be open to feedback. All raids I've been involved with have had good raid leaders. If you listen (make sure to get Vent up and running, you don't have to get a mic, just listen) to the RL and say that you are new, then they will take this into consideration with what tactics they will decide on and describe.
Also, these boards have a fount of wisdom from all members. I've learnt a lot from keeping up to date with these forums.
If you have any questions, then just shout. That goes for on these boards and in-game.
Raids look and are confusing and seem hard to get into at first. But they really add to the game. Enjoy the experience
Oh yeah. It's actually not a bad time to start thinking about raiding. Once Cata hits very soon, we will all be starting from the same point of needing to gear up and learn new raids. An excellent time to get in at the start.