Sorry to add more but one thing many owners forget is to clean their CPU & GPU coolers. Canned air works great for this. You can use a vacuum cleaner but you need to be very careful. Adding fan filters to any intake fans will also help to keep dust out of the case. The filters need to vacuumed at regular intervals but that is easier then having to clean the inside of your computer.
The best AMD/Intel CPU cooler for under $25 dollars is the Cooler Master Hyper 212+. Its only limitation is it won't fit in some much older narrow ATX cases or any "Slim" ATX cases.
Best price: Geeks.com - $14.99 +S/H (
Link)
Newegg installation video --->
http://www.youtube.com/watch?v=c1DGR...layer_embedded