If you've been looking to get involved in the Zend Framework project but haven't known where to get started, Matthew Weier O'Phinney has just to guide for you. It gives you the "short and sweet" things you'll need to know about contributing back to the project.
ZF2 development is ramping up. We've been at it for some time now, but mostly taking care of infrastructure: converting to namespaces, re-working our exception strategy, improving our test suites, and improving our autoloading and plugin loading strategies to be more performant and flexible. Today, we're actively working on the MVC milestone, which we expect to be one of the last major pieces necessary for developers to start developing on top of ZF2. A question I receive often is: "How can I contribute to ZF2?" Consider this your guide.
He talks about what you'll need to get started (including getting a CLA) and includes a few links to some resources to help you get the code you'll need and find some bugs to fix (or file one yourself). He also talks about the details of the project (like naming conventions), where it stands now and what sorts of things you can get started doing right away.