I totally get what you are saying [MENTION=6682376]modernist[/MENTION] I was a bit nervous journeying out and finding a new group as well. What I did was posted on this site in gamers seeking gamers, meetup.com, and pen and paper games. I hadn't ever played with anyone prior to this that I didn't know, so it was a new and fun experience for me.
I ended up DM'ing a great campaign for a great group of guys from level 1-30 in a 4E campaign.
I had to move away from the group so I started looking around again in my new city.
After looking around I met up with a few of the guys in the game at Starbucks and I joined the new group that is running Pathfinder (which I had never played before), I got in with a totally new group that someone else put together for this and we have played 3 sessions so far with the 4th coming up this weekend. It's a lot of fun so far and everyone seems to really enjoy it.
A couple of the guys I play with know each other and have played together before in other games, among them are two that are really into the RPG community here. One actually helps run Neoncon. So I've decided to volunteer my time at Neoncon this year (which should be a lot of fun) and this past weekend I went to the monthly game day here in Las Vegas. I met some more people and joined in on a LFR 4E game. I had a great time.
My advice to you is to keep an open mind, don't be too nervous, just be yourself, have fun, and allow everyone a session or two to work together before trying to get the DM to do anything that you suggest (i.e. ask for Drow encounters).
Before joining a game, I would ask the DM in an email or a face to face meetup beforehand what kind of campaign s/he will be running, what kind of alignment(s) allowed, what genre, what races/classes allowed, if they want a background of your character, and any other valid stuff you can think of. This should give you an idea before you actually join the game if you want to or if they want to invite you. If everything works out and you join up, just have fun and be relaxed.
My 2 cp,
Trav