Useful Links And Good Books

Originally Posted by Salem

Network analyser - http://www.ethereal.com/
Use this to
1. Watch what existing browser / email / ftp / chat client does already
2. Watch what your program is doing different, if you're writing a browser / email / etc

Ethereal is DEAD.
Well, not really... The name has changed, it's now called WireShark: http://www.wireshark.org/

Arduino - HomePage - very cool. It's a predesigned I/O board that you can load C programs onto.