Here are three books I quite like. The first two are old:
1) How to get control of your time and your life, by Alan Lakein
2) The Effective Executive by Peter Drucker
3) Time Management from the Inside out by Julie Morgenstern
If you're looking for strategic advice, rather than tactics, Lakein and Drucker's books are quite good. Their tactics sometimes apply to the 21st century and sometimes don't.