I haven't read too much of iWoz yet, but in the early pages I think Steve Wozniak shares several important lessons. First, if you have a passion for something, go for it. He loves electronics, math, and science, and that love took him a long way. We look for the same thing when hiring people: do they love what they do for a living?

Second, it's important to experiment and fool around some times -- not everything has to have a "deliverable". He created many things just for the fun of it, again following his interests, his passion. Playfully creating these intermediate products gave him the training/knowledge/experience for bigger things he would later develop.

Next, although he never states this directly and may not mean it this way, choose your friends carefully. He describes many early friendships, where he hung out with other people we'd now call geeks, including how he first met Steve Jobs. But he also describes how he wanted to hang out with hippies, because they shared a lot of common beliefs, but in the end they didn't want him around because he didn't do drugs. It sounds like he fell in with other very smart kids, and his moral values were also strong enough that he didn't give in to what was probably peer pressure from hanging out with his hippy friends.