Books that will help you learn about Product Management and prepare for interviews
Cracking the PM Interview
Some good context on what its like to work as a PM, how product managemet differs at some of the most common tech companies, and a good list of PM interview questions.
Decode and Conquer
My personal favorite PM interview book. It has an extensive collection of very high quality practice questions of all types, and most importantly gives excellent sample answers to each question. I highly reccomend it.
Cracking the Coding Interview
This book doesn't apply to everyone, as only some companies ask PMs to go through technical interviews. But, if you're interviewing at a company that does (like Google), practicing up on your data structures and algorithms knowledge will be helpful.