Everything everyone else has said is spot on, especially about drinking a good deal of (but not too too much) water. The best thing about doing this, I find, is that when you feel like you have to go, you actually can go because of the water. If you aren't drinking a lot, feeling like you have to pee and not being able to can be anxiety-provoking and can make your symptoms worse.
I also want to echo what eastsidesunset said about making sure you eat with the pills if you get a short run of antibiotics. The last time I had a UTI, the doctor advised me to do so, and I kind of scoffed. Boy did I regret it the first time I took one of the pills on a relatively empty stomach! Additionally, those antibiotics tend to be pretty strong and can cause a yeast infection, which is probably the last thing you'll want after dealing with a UTI, so try to eat a bunch of yogurt with active cultures while taking the medication to try to prevent that nasty little side effect.
Until things clear up, try to stay away from things like coffee and soda. As for cranberry juice, make sure you continue drinking it regularly (eating yogurt with active cultures regularly will help with this as well) after you're cured. Once you have a UTI, it's much easier to get another one and slip into a chronic UTI cycle, and that is no fun! Feel better!