SSRS and Sharepoint Lists - XML Query Syntax guidance

Hi,

I'm looking for a comprehensive resource on XML query syntax for querying Sharepoint list data in SSRS.  I need help understanding how to use <And>, <Eq> etc and equivalents for T-SQL "where" "and" "or" etc...

I have looked, but can't seem to find anything more detailed than a generic "how to".

SSRS 2008 R2

thanks,

Steve.