Hi Jonathon,
One thing that might help is if you specify which version of ZF you're interested in. Currently ZF1 is stable, it's built to be PHP 5.2 compatible, has been stable for quite some time, and uses very traditional concepts for most PHP developers. ZF2 is currently in beta 3 (I'm told beta 4 is due early next week.) runs on PHP 5.3+ only, uses namespaces, Dependency Injection, is highly modular, and a bit more complicated.
I would recommend starting on
http://framework.zend.com for ZF1, the end user documentation is pretty thorough, there are also tons of blog posts out there, as well as a public (free) book called Surviving the Deep End by Padraic Brady. For ZF2 things get a bit hairier, it's not well documented yet (it's constantly evolving still) but you can start on
http://framework.zend.com/zf2 there is some documentation. There are also a lot of resources on github for zf2, such as the skeleton application (recommended filesystem structure and example setup) available
https://github.com/zendframework/ZendSkeletonApplication
Best of Luck!
Shawn Stratton
Zend Certified Engineer
Senior Systems Administrator - Digital Platforms - Discovery Communications, Inc