1996 jeep cherokee

first you can have a starter rebuilt for about 40-50 dollars second the starter is located under the motor follow the wire from the battery

Starter is on the passenger side of the engine.
If you are confident you can replace it yourself, you could save time and get a lifetime warranty if you buy a rebuilt unit from certian auto parts stores. They will charge a core fee, meaning you have to take your old one back to get a portion of the money back.
I would recomend getting the old one off and taking it in for testing. The machine at the auto parts store will test it several times not just once, and some modern testing machines test the crap out of them to make sure it won't miss a problem.

Now, if you don't know what you are doing, I would recomend buying a repair manual. They have Chiltons and Haynes at most auto parts stores. I prefer the Chilton's but others prefer the Haynes. Their is also a link on the main page of this site to purchase repair manuals. The information in one of these will save hours of frustration trying to figure out how to get parts off, or replaced, as some are trickey.