timing belt change???

I'm changing my waterpump because it's gone the way of the doh-doh bird. My car has 100,xxx miles on it and the timing belt has never been replaced. How much of a pain is it to do it yourself? And how much does it cost to pay somebody to do it for me?  

Depending on the engine you have, here's what it's like on a TDi:

The water pump is run by the timing belt, so you've gotta remove that anyway. To get there, you will have to remove some things like the coolant overflow reservoir (I just pinched off the hose and laid the reservoir to the side), the intercooler-to-intake pipe, the injection pump lines and the passenger-side motor mount. Then you remove the serpentine drive belt and the upper timing cover. Then you remove the vacuum pump and valve cover. Turn the engine to top-dead-center and lock the cam in place with the special cam-locking tool. There is also a lock pin for the injector pump, which your car may not need if it's not a diesel. And finally, there is a crank-locking tool that should be used as well. After you've gotten to TDC and locked it all down, you can remove the timing belt. On the TDis it's recommended that you replace the timing rollers (pulley and bearing assemblies) as well which I'd recommend anyway, especially if you are not the first owner of the car and don't know how it was driven or taken care of.

I did my first one in September 2007 on my own car, and it took about six hours. Now that I've done it and know what to expect, I could probably shave that down to 2 or 3 hours. It does take some time to do, but I only spent $375 in parts/antifreeze instead of $600+ to have a mechanic do it.