Is this your first book? It's not bad, really. I was particularily impressed by the spelling and grammar (I didn't see one missing or mispelled word). I could definitely 'feel' your effort. You'll be an excellent writer someday, so instead of offering criticism about the story, I'll offer some advice in general.
1. Keep thinking, keep writing. Yeah, duh.
2. Study character development. Really work on distinct personalities/speech patterns. (Wuggle is a good step in that direction)
3. Study the writing style in books you like. They should help you find ways around dispensing information without exposition...the whole, 'show don't tell' thing. (Ultimately, this is something learned with time and practice, but finding examples helps.)
4. Find people (friends, family, teachers, writer's groups) who can provide regular feedback. Other people tend to see problems in our writing that we miss. The people on this writing forum I've noticed are generally helpful too(personally, I'm always available to put in my two cents worth), but it can be more difficult to critic on a computer screen than a piece of paper sometimes.
Hope this helps, Esoteric.