Network World — With companies running lean and mean, professional development has increasingly become an individual sport. IT workers have learned to fend for themselves to develop needed skills and gain new mindsets for managing more effectively and adding more value to the workplace.

Many professionals are turning to webinars and other online venues to do this, but a good number continue to get meaningful career advice through the tried-and-true method of reading a good book.

We asked four IT professionals from different industries to share the books that have influenced them in their own professional development.