Welcome!  Im fairly new to modding my Tracker too.  I can do a basic rundown of things for you until someone more knowledgable is around.
Lifting:
-Coil Spacers - (Variable, make em however big you want)  1.5 Inch spacers is good size.  Any more than that and you may have camber issues in the front.  These will provide somewhere around 2.5-3 inches of life on the front, 1.5 inches of lift in the rear.  I hear this evens the ride out nicely.
-Body Lifts - I dont like them but, they 're cheap and effective for bigger tires.  Ask around, there is some good info about how to make these.
Tires
-Stock tire is 205/75/R15
-Biggest you can go without any lifting is around a 235/75/R15
-From what I hear 31" tires are a wonderful compromise between daily driving and off-roading
Rims
-Stock is 15 x 5.5
-You can get some wider rims if you like that look.  15 x 7 or 8" rims look good on Track/Kicks
-Stock backspacing on rims is something like 4".  Try to go a little less if you plan on lifting and getting bigger tires.  3.5" would work but, I beleive its 2.75" that alot of members here like on serious rigs.
-Remember, Zuki rims need a 5x5.5 bolt pattern (Most jeep rims wont work on them.  Ford truck rims oftentimes are good replacements.
Thats the basics, more knowledged people can explain things like lockers, SAS setups, and other things. Hope this info offers a decent starting point.
-Rob