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.
A Business Object Model is sometimes more generally called a Domain Object Model (just in case you are dealing with a non-commercial domain). A good place to start your research is Anti-Pattern: Anemic Domain Model.
You may not need a domain model if your application is dead simple and there is very little business logic. However if you plan to maintain the application and evolve it to the ever-changing "business" needs then the development (and evolution) of a Domain Model is worth while.