I realize the post is slightly old, but you never know when someone is going to come looking and this isn't like politics, this is beer and important.
On the north side of town there is a ABC fine wine & spirits that has a decent enough selection of beer. If you can stand to deal with people who are slightly incompetent then you can order pretty much whatever you want. They have Spaten Optimator, St Bernardus, Delirium, and 5-6 other belgians, various Samuel Smith beers, Murphy's, various Lagunita beers, Sam Adams(like the Baltic Porter and such), a couple framboise, and a couple other decent beers. Enough to find something enjoyable at least if you don't feel like driving to Tampa.
If you want a bar to go to there is a little place with good prices on the north side called Burgers & Brew off of Duff road. They have a pretty good bottle selection and something new on draft every week along with cheap prices. 2-3 bucks a bottle and draft for most of it. Miller Ale House on the N side of town has 20-30 drafts.
If you don't mind a little drive then Dunderbaks in Tampa probably has one of the best beer selection in Central Florida. 55 drafts, a beer engine, and 400+ bottled beers. Not to mention the awesome German food. They sell most of the beers to go.
There was a homebrew shop in Lakeland until a couple years ago but the guy who owned it died. I used to sit and drink moonshine with him while he told me stories about storming the beach in Normandy
My wife liked him enough that she didn't mind stopping for a few hours with me so she could flirt with him.