I've been working with Java for several years now and it's time for me to expand to other languages. I've decided to learn Python and have now just started looking into where to begin. I'm wondering if there is one, maybe two books out there that are considered to be the best start when learning Python?

Dive into python has a good reputation. A good part of learning python is learning the standard library. Note that the library has been reorganized in python 3, so that some module names may differ, and some code may run with python 2.x and not python 3.x.

Since you've got several years programming experience, I think the best place for you to get started quickly is The Python Tutorial from Python official documentation ;)