It's also important to watch (maybe not associate with) people in the field who aren't going places. Knowing what to do can help you succeed, knowing what NOT to do will help you from failing. Even if you do everything right, doing one thing wrong can put you back to the beginning where you have to start over. A lot of successful people can tell you what to do right as well as things to avoid, but I think stories about why someone failed can be just as good and in some cases better than the advice given to help you succeed.
I think a good book that many magicians wouldn't have read (rather, the average magician who doesn't know about books that don't contain tricks) that gives a good view on how to be successful is Malcolm Gladwell's 'The Tipping Point'. It hits on why things become popular, ranging from small communities all the way to national trends. It may seem unrelated, but it talks about different people in the book and how knowing what types of people to network and connect with can help you succeed.
It's an interesting read at any rate, and something to get you away from books on magic for a while (a few days for fast readers, a week for someone who has no time and drags through it slowly).