This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
This is a generic question. So I'll give search tips rather than try answering that.
You HAVE to understand what threads are, what monitors are, and what wait and notify methods really do. You could start here JavaWorld Article: Synchronizing Threads In Java which is probably one of the few articles that has any mention of a "potential monitor" to an object and implicitly distinguishes between an "object" and a "monitor".