OSTI, the Office of Science and Technology Information is worth bookmarking.  It serves as a portal for most of the federal goverment’s information, reports and data for 18 agencies:

Agriculture,Commerce, Defense, Education, Energy, Health & Human Services, Interior, Transportation, Environmental Protection Agency, Library of Congress, National Aeronautics & Space Administration, National Archives & Records Adminstration, National Science Foundation, and the US Government Publications Office.

Terminology and thesauri might help in your information searches.

This site is a gateway to DOE collections at ScienceAccelerator.gov, global science via WorldWideScience.org, scientific research data as an open government initiative, and the OSTIblog.

Much of this, they declare, is outside Google’s purview — in the “deep web.”