The Congressional Research Service (CRS) is the public policy research arm of the US Congress. With its $80 million budget and 800 employees, it issues about 3,000 briefs, reports, short issue papers and longer position papers per year.
An arm of the Library of Congress, the Congressional Research Service is renowned for its non-partisanship and in-depth analysis, but it does not make its reports available to the public. However, it cannot prevent members of Congress from giving them out individually and some government agencies from posting reports they find relevant. Perhaps 1000 have become available on the web.
There are a number of places you may want to search for these reports.
For SU database sources on current legislation look at the main U.S. Government Information tab