The Elements of Style, by William Strunk. Get a daily schedule book and use it. Carry it with you. Keep a regular schedule. It's your life.
Every moment is a moment of choice.
Choose what's important. There's no substitute for sheer number of hours at work. There aren't any shortcuts, but there are ways to use time as efficiently and effectively as possible. For example, The Student Academic Center offers courses in study skills, including time management, reading and note-taking, library use, etc. There are courses for credit, personal counselors, and computer tutorials.