Make & Build Stuff
You don't need to buy an Arduino, you can "make" one using a breadboard and a lot of parts—but let's say you want to dive in and pick up an Arduino with enough projects to teach you how things work, and help you explore microcontroller basics. Covers LEDs, transistors, motors, integrated circuits, pushbuttons, variable resistors, photo resistors, temperature sensors & relays. I suggest the Arduino ARDX experimentation pack for $85. If that breaks the bank, choose from less expensive packs: a $65 starter pack, a $50 budget pack or just a straight-up $30 Arduino.
If you can scrounge up the parts on your own you can always download and print up the free booklet which includes all the lessons. If you're the book-learnin' type, there's a great little one called Getting Started With Arduino, $13, written by Massimo Banzi, co-founder of the Arduino Project.
