Stores
http://www.robotcombat.com/ The good stuff.
http://www.jameco.com/ Really cheap stuff.
http://www.active-robots.com/ Great stuff if you live in England.

Software
http://www.enigmaindustries.com/EDTSim_Demo.exe You need to check out this demo, lots of useful info on building robots; motors, batteries, etc. And it simulates all the stuff together. Well at least the driving portion.
http://www.mobotsoft.com/index.htm Another program that simulates the AI.

Organizations
http://robotics.nasa.gov/ NASA's Robotics Education Project
http://www.rssc.org/ Robotics Society of Southern California.
http://www.robots.net A news site and a community made by other robotics hobbyist.
http://www.servomagazine.com/ A magazine that covers the hobby of building robots.

Other cool robots
http://abrobotics.com/ Useful tips and hints on building robots.
http://www.snakerobots.com/main.htm Snake robots made with the Basic Stamp 2.
http://home.epix.net/~iracerc/stamp.html R2D2 type robot made with the Basic Stamp 2.
http://www.robotprojects.com/index.htm A website that supports the use of the OOpic in robots.
http://www.geocities.com/mikegotis/manatron.html Humanoid robot made with a collection of Basic Stamp 2 chips.
http://reconnsworld.com/ A website recommended by Fred.

Johnny Five
http://www.johnny-five.com/ Our next robot. They also have a lot of pictures there.
http://www.robotic-endeavors.net/ Johnny Five's Blueprints!

Games
http://www.aow-west.com Art of War website, a StarCraft clan.
http://www.totalwarcenter.com/ Rome: Total War, Fansite.