Promote yourself to the owners/managers of the places you want to play. Call each place and find out who the person is who books acts. Then put together an informative flyer about your group/act. Not too long or too short. Have at least 2 or 3 ways to contact you (home phone, cell phone, email...) Include what you've been doing, if you've been touring, etc.
Include w/this a demo tape/CD. Just a couple songs will do.
Go in one night when that person is working and give them your info and demo and make a good impression...odds are they'll be busy, so don't think a 30 second interaction is a bad thing. It's not.
You'll prolly get an off night to start, like a Tuesday or something. Check out clubs/bars that have drink specials, because people will be coming to the place for drinks, anyway. It's easier to play for more people that way and honestly, when you're starting out, it's all about how many ears are listening to ya.
After a while, you could either upgrade clubs or nights to a weekend or so.
It's all rungs on a ladder, man. One step at a time. Use your friends, too, to help you. Word of mouth and someone's own personal excitement about a band is the best publicity you can ever have.
Let us know what happens. Good luck!