Thanks for the advice.I truly enjoy my Arduino. Even though I've only done the blinky tutorials, I've found my programming experience has allowed me to really play around with it regarding how it reacts and making modular code.So far, I've spent about $300 on parts from Adafruit. The Make book I referred to has the experiment kits for sale for about $100 each (total of two), and then they have the tool kit itself for even more money. Adafruit has a decent kit with solder for about $100. By the time I add shipping (and maybe a few extra small parts) it gets up around $400.
I was hoping there would be a good simulation software that teaches the concepts.
Guess I'll have to bite the bullet and buy more parts. I will consider the books, but if they're pricey they'll have to wait. If it comes down to books or parts to experiment on, maybe I'll suffer and get the parts first. At least there's info online to look up.