God help you if you want to learn about linguistics on you're own. The book helps enormously, but half the time it's very dry and the other half it's technobabble (or linguobabble, I guess) and it doesn't do a good job of reminding you of things you were supposed to have learned earlier on. For example, I took a break between chapter three and chapter four, and forgot most of the stuff from the earlier chapters. I had to go back and reread them. I decided to start taking notes, and that helped, but it would've been nice for the exercises in the book to be a bit more clearly laid out.
But it did have some nice exercises, overall great presentation of material, and I did learn a lot.