What types of books do you recommend to start ups?

The Hard Things About Hard Things by Ben Horowitz is great

4 steps to the epiphany Anything by Eric Ries

Title sounds like hyper capitalism, but content is really great: high output management by andy grove.

Inspired: How to Create Tech Products Customers Love

Hacking Growth: How Today's Fastest-Growing Companies Drive Breakout Success. It's actually more about the grow, but it has been very illuminating