There were a few hurdles in the release of the Yosemite public beta, primarily in people successfully downloading the installer. Now that it's more likely you actually have the installer, Joe Kissell has some tips for you on running a Mac OS Beta. He's been beta testing since 10.3, so he knows of what he speaks. He's put together a great set of tips in Take Control of Beta Testing Yosemite, the latest title from Take Control Books. This one has a suggested price of $5 and is available via Leanpub to allow for quicker turnaround on updates (since betas can evolve dramatically). This is more than just a grand tour of new features, it also discusses what beta testing entails, tips for both before and after installing, and advice on how to report bugs.
Check It Out: Take Control of Yosemite Beta Testing Released