Here is a select snippet that will return user and role permissions on objects in a database. I have a proc that I run every day that gathers logins, users, roles and their permissions and dumps it to a file for auditing purposes.

select protecttype, action, so.name, s.name from sysprotects sp inner join sysobjects so on so.id=sp.id inner join sysusers s on sp.uid=s.uid and s.name <> 'public'