The water pump is located just behind the timing belt on the front of the engine.
you need to remove any obstructions to the area, i.e brackets and such
remove the accessory belt (drives alternator, power steering, A/C, etc.)
remove the timing belt covers... there's three of them
remove the timing belt itself before you can have access to the water pump.
If you haven't replaced the timing belt yet, it's highly recommended that you do while you have everything apart and the timing belt already off. Whether you put the used one back on or replace it with a new one, you do need to go to the dealer and get a special spring that will tension the timing belt tensioner for you.
Here's a picture of the front of the engine with the timing belt, it's covers and the location of the water pump. I hope this helps.