The 7 Habits of Highly Effective People: Powerful Lessons in Personal Change
Stephen R. Covey · ★★★☆☆ · 372 pages · 1989
Though I heard a lot of people recommend this book I feel that only the first three habits were actually useful. The others are more of stuff that you'd read about in How to Make Friends and Influence People. Basically the gist of the first three habits since those were what I found useful are to make a plan sort of a personal consitution which doesn't change and lead your life and goals according to that plan.
Further things that were recommended: read a book a week, exercise everyday, sharpen the saw and be knowledgable everyday to do things.