Committees are extremely important; most of the work of Congress is done in committees. These sources contain information on the committees and the committee members, including contact information. Some sources includes ratings of members of Congress on particular issues.
Want to find out what committee your representative serves on? Check:
Committees may commission special research papers prior to deciding on a bill. These "Committee Prints" provide highly valuable situation reports, statistics, briefings, background information, and legislative analyses. Some of these reports are written by the Library of Congress' Congressional Research Service.
If you have a title, be sure to check DELCAT. Keyword searching may be easier in some of the full text databases.