i'm also new to jeep ownership and want to lift mine as well. i know that a 2.5 inch lift will allow for about a 31 inch tire, and most of the better looking "manly"
tires look better, bigger if you know what i mean. i'm looking at a 3-4" lift myself but there are a lot of other things you have to think about when you go that high. i would suggest you look at and read the thread about lift kits on the main page. there is some good, useful info on there and some links to sites to get pricing for individual parts and kits.
please let me know if you find this info useful.
enjoy your jeep