Well, for starters, here is a KB on how to update your MAPI/CDO objects on the BES: KB15779 - View Document
Is the new cluster 2007 or 2010? If so, there's no single document that will cover that for you, but the installing and configuring guides is a start. BES doesn't care if it's clustered or not, just the version.
No Exchange updates should ever go on the BES.