We do not have any specific examples for obstacle avoidance for the Zumo 32U4. You might consider modifying the "FaceTowardsOpponent" example including in our "Zumo 32U4 Arduino library" on our GitHub page for the Zumo 32U4. If you get started with your sketch and run into problems, you can post what you have so far and we would be glad to offer some suggestions.
I do not have any specific recommendations for books you might look into. However, the Arduino Playground is a good place to look at what other people have done:
Additionally, the Arduino forum is great when you are looking for Arduino programming advice: