How I wish I’d read this book at 17 years old; so many wasted years. If you’re a young man, you can do better, and this will help. J.C. Ryle’s “Thoughts for Young Men” is an absolute must-read. And it’s not a long book, either. And it’s free online.
No excuses, guys. “Man up” and read this (PDF).
More formats available here (Kindle and ePub), by the way.