Coronavirus.gov (now redirects to CDC page)
Department of Homeland Security (archive)
House Oversight Committee (3/11/20 hearing)
House Select Subcommittee on the Coronavirus Pandemic (see also, 2020-2023 Committee archives)
Department of Public Health
Governor Newsom and state health officials briefings
University of California
UC San Diego
UC San Diego Health
COVID-19 Web Archive (via Internet Archive)
LitCovid, from the National Library of Medicine, tracks and provides access to COVID-19 articles in PubMed.
The Copyright Clearance Center has compiled a list of publishers and organizations providing access to COVID-19 research.
A community-sourced list called Vendor Love in the Time of COVID-19 can help identify "licensed content that library vendors are making available on free or modified terms during the COVID-19 outbreak."
Introduction to COVID-19: Pandemics Past and Present - This database from HeinOnline compiles publications on the various ways COVID-19 has impacted every aspect of life. Areas of focus include Economic Impact, Global Impact, Health Care Impact, Societal Impact, Vaccination, and Past Pandemics. Includes an expanding selection of scholarly articles and links to external resources. (Remote access is limited to UCSD affiliates.)
Digital Public Library of America (DPLA) has published a free ebook, The Covid Archive: a finding aid to government documents related to the Covid 19 pandemic, that indexes more than 3000 federal and state government documents identified by the Covid Tracking Project and digitally preserved by DPLA.
A separate COVID-19 guide from other UCSD librarians focuses on science/research aspects.
Many other libraries have created helpful guides to resources; try a Google search using (coronavirus OR covid-19) libguide as search terms. The Federal Depository Library Program also has a guide to resources.
Tara Calishain's "CoronaBuzz" points to great "new resources, useful stuff, research news, and more."