Electronics Links
A great place to buy parts: Jameco Electronics
A place to buy parts especially for "mad scientist" and robot type projects: http://www.hobbyengineering.com/
A huge selection of build-it-yourself kits is available here:
More kits, including the Arduino microcontroller. http://www.adafruit.com/
The company that makes the Propeller microcontroller: http://www.parallax.com/
A free book on Digital Signal Processing: http://www.dspguide.com/pdfbook.htm
The easy to use electronics simulation software: Multisim
Electronics hobbyist web page.

A local store to buy motors, used equipment: C & H Surplus.

LEGO Mindstorms Robotics LInks
Official LEGO Mindstorms Robotics information pages.
Lists of LEGO parts and sets.
Another site for LEGO parts ands sets.
Site for buying and selling LEGO parts and kits.