I don't know if they're still available, but the Forrest Mims electronics books that they used to sell at radio shack are absolutely awesome, teach theory and h

I don't know if they're still available, but the Forrest Mims electronics books that they used to sell at radio shack are absolutely awesome, teach theory and have tons of simple (and not so simple) circuits you can build. They're mostly analog though, digital is much easier, just connect a few parts together and then it's all code.