Sparkfun (http://www.sparkfun.com http://www.sparkfun.com) has some good tutorials. "Beginning Embedded Electronics" is a good place to start. I personally got

Sparkfun (http://www.sparkfun.com http://www.sparkfun.com) has some good tutorials. "Beginning Embedded Electronics" is a good place to start. I personally got started with microcontrollers and digital electronics by reading "The Microcontroller Idea Book" by Jan Axelson. It's a bit dated, but very well-written, and for me it was the first time that hardware really "clicked". I still refer to it from time to time for ideas for interfacing I/O devices.