Here are the top 4 books on productivity that I recommend:
1. The 7 Habits of Highly Effective People by Stephen Covey
2. First Things First by Stephen Covey, Roger Merrill, and Rebecca Merrill
3. Getting Things Done: The Art of Stress-Free Productivity by David Allen
4. How to Get Control of Your Time and Your Life by Alan Lakein
5. Don’t Waste Your Life by John Piper. This is to get at more foundational issues regarding priorities and how we should be spending our time.