These are the websites I use regularly when I need to look stuff up, ask for help, find a good walk-through guide, do some research – you get the idea!
Petri Knowledge base – Been around as long as I can remember.
Computer Hope – Another long time favorite.
Computer Performance – Anything and everything Windows.
Command-Line Kung Fu – For the avid CLI user.
The Bryant Advantage – Resource for Cisco training videos and literature.