All About Circuits - an e-textbook about electronics
eCircuit Center - advanced topics in electronics
ePanorama - all you ever wanted to know about electronics
EEWeb - Electrical Engineering magazine and community
Circuit Cellar - my favourite embedded electronics magazine
Discover Circuits - a huge collection of schematics
www.alldatasheet.com - data sheets (free of charge, no registration)

Microchip PIC microcontrollers:

Microchip - manufacturers of PIC microcontrollers and other ICs
Dontronics - advanced hardware & software products
PIC List - huge source & resource library
Fast Forward Engineering - a good PIC FAQ
Parallax INC. - a hands-on introduction to microcontrollers

Other technical resources:

Docklight - shareware RS-232 terminal emulation
1-Wire Search Algorithm (taken from Maxim/Dallas AN 187) (download C file)

Non technical:

Home Toys - my favourite home automation e-magazine
Smart Homes - the human aspect, Part 1 & Part 2 - an article I wrote for Home Toys
Metalgrass software - shareware products, free downloads

Disclaimer: CONTROL G.S. is not affiliated with any of the mentioned web sites.