Joe Rinehart wrote and article November '04 focusing on using Beans and DAOs that was recently mentioned on the CFCDev list.  If you are somewhat new to OO development, I strongly urge you to read this.   Even if you aren't you may find yourself picking up a small nuance here or there that you may have previously overlooked.  I attended a class by Joe on this subject, involving taking legacy procedural applications and refactoring them with this model, and really gained a lot from it.  While some people's opinions differ in the specifics of implementing this approach, the concept itself is one that is pretty universal.