If you are interested in below topics, then followings are my recommendations for books . I hope you won’t be disappointed after reading these books.

Professional Services

• David Maister’s work is must read for any one interested in professional services firms, especially for aspiring managers.
  • Managing Professional Services Firm
  • The Trusted Adviser
  • True Professionalism
• Marketing Professional Services By Mike Schultz
• How to Make Partner and Still Have a Life

Sales

• Mastering Technical Sales: The Sales Engineer’s Handbook

PLM

• Engineering Documentation Control Handbook

 Software Development

• Software Architecture in Practice By Paul Clements
• Essential Scrum: A Practical Guide to the Most Popular Agile Process By Kenneth S. Rubin

Technical  Writing

The Elements of Style By William Strunk & E.B. White

Psychology

• Quiet: The power of introverts in a world that can not stop talking By Susan Cain

If you are introvert then reading Quiet will help you to cope with challenges in this extrovert world.

• Influence: The Psychology of Persuasion By  Robert B. Cialdini
• Emotional Intelligence By Daniel Goleman
• The Biology of Belief: Unleashing the Power of Consciousness, Matter, & Miracles
• Mindset – The New Psychology of Success

Self Help

• Essentialism
• Think and Grow Rich
• Rewire

General

• Thinking in Systems: A Primer