
I like reading. Sometimes the book turns on the proverbial light bulb. These are a few of the professional development books that did this for me:
Peopleware : Productive Projects and Teams, 2nd Ed. by Tom Demarco & Timothy Lister (at Amazon)
The Inmates Are Running the Asylum: Why High Tech Products Drive Us Crazy and How to Restore the Sanity 2nd Edition by Alan Cooper (at Amazon)
Software Project Survival Guide by Steve C McConnell (at Amazon)
Dig Your Well Before You're Thirsty by Harvey Mackay (at Amazon)
Getting Things Done: The Art of Stress-Free Productivity by David Allen (at Amazon)