a hanes manual at advanced auto parts or any other store will run you about 15 bucks and is well worth it, but if you want to walk the waters on your own here's some tips.
1. Depending on your engine size this should be fairly easy. You will need a full socket set and probably a jack and some stands.
2. Be sure you drain all the coolant out before you start, using the pitcock at the bottom of the radiator.
3. remove the nuts on the belt wheel before loosening the belt, and replace them after putting the wheel on the bolts and tightening the belt (learned this one the hard way).
4. Buy a can of Gunk engine and bolt soak fluid (looks like a white and orange paint can) soak all your bolts and things in here. (makes things easier in the end)
5. use brown lunch bags for all your bolts/screws and keep bolts from tires seperate from bolts from the pump (for example).
6. once you start finish this job before turning on the tv or doing anything else, nuts and bolts have a habit of walking away if you leave them around.
7. The gasket is the most important part of this job, once you get the pump off you need to scrape the old gasket off of the engine side of the water pump. (you won't need to do this to the old pump obviously) A putty knife works well, but be sure you don't scratch the metal under the old gasket which is part of the engine block and will just cause another leak. Apply gasket sealer to both sides of the gasket right before you put it on and smear it to cover every inch of both sides with your fingers (it won't kill you). Hang the gasket on the bolts to be sure of where it is, don't just slap it on there and hope to line it up, tighten all of your bolts very well.
8. Prepare to run into problems, this won't take an hour, probably more like a whole weekend. When you refill fill your radiator and your reserve tank, run the car, wait for it to cool, then do both again.
You should be able to do this, just don't expect it to be a breeze, and please buy the repair manual it will help tremendously!