I would have recommended the same books. In addition to that please read Books by Peter F Drucker on Management, strategy and how to treat Humans.

In startups, human interaction is most important more so than a huge corporation because both employee and employer needs to understand the importance of each other. Make sure you treat them right and make sure they are excited,valued and well treated.

Get a mentor, you need to keep them engaged, request with specific questions, ask for suggestions. No one wants to receive a specific mail asking me to be a mentor. they would rather send a note/ give a suggestion which will help you.

All the very best for you and company, and keep us posted on how your journey is.