This page is actually an advice and web links page.  These links are sites that I use everyday so they are all safe but, I cannot guarantee that the site has not changed so you are on you own.

SHOPPING:
NewEgg.com : New Egg is one of the most reputable sites for online computer parts purchases.  I am a little worried about getting Hard drives from them as they have gone on a "green" kick and ship me an oem drive packaged in paper and not foam which is what they should be using.  Also use Fed Ex when getting hard drives as UPS beats the crap out of their boxes.

PriceGrabber.com : My first choice for competitive list of items based on price.

Pricewatch.com : great place to get a competitive list of items based on price.

ResellerRatings.com : get reviews for online web sites.  Good way to double check the online shop you are dealing with will not rip you off and give good quality items.