I lived there for a few years, but turned of legal age just before I left, I wish I could be of more help!
Total Wine is a chain beer/wine/liquor store and it's huge. They have a pretty good selection of beers, you can find their catalog online, prices listed.
Orlando Brewing usually offers some interesting choices.
The Mellow Mushroom on Aloma is part of a chain, but that's where I had my first DFH 90 and Rogue on tap. They usually have some regional stuff there in addition to the more commons and try to feature a few new/seasonal beers monthly.
Old Germany on Semoran/436 carries some good beers, but it's a little pricey, I've never had timely service (everyone is friendly, but they must be understaffed), and the food is sub-par; I didn't think it was possible to mess up spätzle.
I hope that gets you started!
Also, if you're out all night with the pals, Wally's on Mills opens around 7AM, cash only--but of course I wouldn't know anything about the place!