Where to start depends on what interests you. If electronics, get some of Forrest Mim's books, fun projects using cheap parts. If programmable electronics, get a "what's a microcontroller" from Parallax Inc. If it's alternative energy, get some rechargable batteries, motors, solar panels and play with that.
The main thing is to find something that you really want to play with. Then the learning becomes fun, and when it's fun you learn for the same reason a monkey plays with itself. Because it feels good!
Jonathan