AgNIC (Agricultural Network Information Center) - Directory of quality agriculture-related databases, datasets, and information systems.
Chemfinder.com - Searchable database 75,000+ unique substances from 350+ sites. Property data, chemical structures.
E-Answers - Extension and outreach publications produced by land grant universities. Agriculture, forestry, fishing, family/consumer issues, lawn and garden, child development, 4-H/youth, environment, public policy, economics and water quality.
Regulations.gov - Find, review, and submit comments on documents published in the Federal Register, the Government's legal newspaper.
Science.gov - Public access to the government's scientific and technical information.