Ask HN: Books and Resources for CTOs growing pass the startup phase

I'm in the fortunate position to be at a company that is quickly growing from small/startup size to mid/large size. Unfortunately I've seen too many "startup" CTOs that have difficulty making the transition successfully with the result that they either fail their company or are replaced.

Does anyone have suggestions, books, mentoring programs, or advice they could pass along. I love this company and the team we have built and want to give us the best possible chance for success.