I see some great options shared already. Here are a few more great books!

Quick reads:
1) Simple Numbers, Straight Talk, Big Profits! - by Greg Crabtree - Easy read - takes the mystery out of accounting and shares the steps to be profitable.

2) Jab, Jab, Jab, Right Hook: How to Tell Your Story in a Noisy Social World - by Gary Vaynerchuk. Advice/Examples on how to build an authentic following and how to leverage different social media channels.

3) Scaling Up: How a Few Companies Make It...and Why the Rest Don't - Verne Harnish - includes the four major decision areas every company must get right to grow and offers tools/techniques to use.

Feel free to reach out if you have any questions. I specialize in helping start-ups refine their brand positioning and business model as well as guiding established businesses looking to grow their revenue.

Best of luck!