I'm a newbie ( since October 04 ) to playing gigs but I can tell you there's lots of great advice on this forum, I just got some earlier this week from many the members. You can read all the great help I got here: http://www.synthzone.com/ubbs/Forum37/HTML/011063.html
Here's what I can tell you based on my limited experience. Initially, I had some help from a old friend who has been a OMB for lots of years. But, now I'm pretty much on my own.
Here's what I have done recently to get some gigs. There are a couple of local coffee houses I approached about playing. One is a Starbucks and the other is an independent operation. Both establishments offer entertainment. Since they don't have an entertaiment budget, they will set me up to play, feed me all the coffee drinks and food I care to imbibe in and also place a basket for tips. This Friday night will be the first time I'm giving it a try for the tips and refreshments only type gig. I checked with another musician a guitarist whose worked the 2 coffee houses and his comment was that the exposure has was great, he's booked other paying gigs after people heard his playing at the coffee house. My feeling is that if I didn't have these 3 up and coming gigs I'd just be home playing for my wife and the dog anyway. I think it's worth a shot,especially since at this point I'm not depending on gigs to pay the bills. Good Luck.