I've recently published a second CRM related reporting services project on codeplex. This one illustrates how to get a list of all files related to a CRM account. This includes files attached directly to the account or via related objects (e.g. contacts, opportunities, cases), and also includes both file and email attachments.
Most of the work is done in the SQL, which I've written as a set of SQL views for ease of reading, rather than embedding all the SQL in the report.
The project also illustrates how to link to CRM objects, within a report, as the report contains reporting services actions to display the CRM entity forms, and also actions on each file to link to the CRM file download dialog.
This report is written so as to take parameters from a ISV.Config button, as described here