Gerber’s book on how to stop working in your business to free up time to work on your business is fundamental reading for someone who is still working on the tools. You need to understand the importance of breaking that thinking that only you can do the job as you want it done. How can you set up processes that you need to skill up your team to do the job, so you can run the business. This books helps you to grow from 3 employees to 10 and beyond.
The Lean Startup is a great book for understanding how to move more quickly, especially with product design.