Or if you want to overclock...
Honestly water cooling is overkill for a regular PC user. There are many other ways to keep your computer cool and quiet.
Here are my silent cooling recommendations:
1) The NV Silencer will keep your graphics card quiet.
2) Zalman HSF for your processor. ($40-$50 on Newegg)
3) Get a Power Supply which is efficient / fanless. Never buy cheapo PSU's though, this is the one component that can ruin everything else. Here's a good Zalman, but if you plan on upgrading your PC soon an ATXv2.0 PSU is recommended.
http://www.newegg.com/app/ViewProduc...103-213&depa=0
4) as far as case cooling goes, you want to bring air in through the front bottom of your case and blow it out the back right below your power supply. 80-90mm ball bearing fans (the cheapest ones) are going to be loud. 120mm fans are much quieter. You could buy 2 decent 120mm fans (front&back) and as long as you aren't running a hot processor (Prescott) you should be fine.
If you aren't worried about silent, then just make sure the ambient temp in your case isn't more than a couple of degrees above room temperature (w/ fans blowing in the front and out the back). Unless you are overclocking you should *not* need to change the cooling on your vid card / processor. If you have a proper fan setup make sure you keep your cables (IDE, floppy, power, etc) tucked nice and neat so the air can flow through your case easily.
Here are some nice case fans if you need some:
http://www.hardforum.com/showthread.php?t=849207
Keep in mind that these fans are not quiet, but they are cheap. I bought 15 of them (they drop to $0.99 per fan w/ free shipping) and put an extra fan in each of 5 cases.
e-mail me brent at woodle dot org if you have any other questions...