I'm currently taking this glass blowing class at San Francisco State University, it's offered as part of their 'extended learning' program (which means you have to pay for it separate from university fees (i.e. they make more money from it), and it also allows you to take classes while not being a member of the student body(which is really cool)).
The most difficult part of learning how to, and actually blowing glass is finding a place to do it. You can look in the yellow pages, search google or try putting your zip code into this search in order to try to find hot shops in your local area. There's usually someone blowing glass in most major cities (and quite a few non-major ones).
When you find a place with the tools, contact them and see how much it would cost to stop by and use their equipment. Several places I've seen only require you take a basic class at their centers in order to come back and rent shop time.