The website of the Council on Environmental Quality (CEQ), the White House agency responsible for coordinating federal agency compliance with the National Environmental Policy Act (NEPA), is located at http://www.whitehouse.gov/ceq/. CEQ operates NEPAnet (http://ceq.eh.doe.gov/nepa/nepanet.htm), which it describes as a central information hub for NEPA. The site includes links to CEQ's NEPA regulations (which are codified at 40 C.F.R. §§ 1500 to 1508) (http://ceq.eh.doe.gov/nepa/regs/ceq/toc_ceq.htm), executive orders (http://ceq.eh.doe.gov/nepa/regs/executiveorders.htm) guidance documents prepared by CEQ, (http://ceq.eh.doe.gov/nepa/regs/guidance.html), NEPA websites maintained by thirteen federal agencies (http://ceq.eh.doe.gov/nepa/agencies.htm), lists of NEPA contact persons at federal agencies (http://ceq.eh.doe.gov/nepa/liaisons.cfm), downloadable copies of CEQ studies and annual reports, and statistics on filings of environmental impact statements (EISs) (http://es.epa.gov/oeca/ofa/act.html). NEPAnet also lists EISs available for review and it provides access to a digital library of documents describing how various agencies comply with NEPA's EIS requirement (http://ceq.eh.doe.gov/nepa/documents.htm). NEPAnet includes a webpage with links to online environmental data sets to assist in environmental impact assessment (http://water.usgs.gov/eap/env_data.html).

EPA maintains a webpage devoted to information about environmental impact statements at http://www.epa.gov/ebtpages/eenvironmentalimpactstatement.html. It includes a case study available at http://www.epa.gov/seahome/eacase.html that takes a real-life example of an environmental impact assessment and leads the user through the assessment process using maps, photos, interviews, and simulated flyovers of the project area.

The National Association of Environmental Professionals (NAEP) has a NEPA Working Group devoted to improving how environmental assessment is performed under NEPA. The group's homepage is at http://www.NAEP.org/NEPAWG/NEPAWG.html. Links on the site include papers summarizing important court decisions in the history of NEPA (http://www.NAEP.org/NEPAWG/content.html), and recent developments in NEPA litigation (http://www.NAEP.org/NEPAWG/recent_cases.html).

NEPA's EIS requirement is the most widely emulated feature of U.S. environmental law throughout the world. CEQ's NEPAnet maintains a webpage with links to environmental impact assessment agencies in 35 countries (http://ceq.eh.doe.gov/nepa/eia.html), and to the webpages of dozens of nongovernmental organizations and international entities involved in impact assessment. The International Association for Impact Assessment maintains a website (http://www.iaia.org) that provides information concerning how impact assessment is conducted around the world and what are considered to be best practices for it.