Many government health and regulatory agencies have released guidance, rules, best practices, and general information on COVID-19. Here are several COVID-19 resource pages from some of these agencies.
CDC's Detailed Guidance on Return to Work
CDC's Interim Guidance for Businesses and Employers on COVID-19
The World Health Organization's "Advice for the Public" on COVID-19
Department of Labor Wage and Hour Division COVID-19 Website
OSHA's COVID-19 Website
Resilience in a Box: Disaster Preparedness Resources for Small Businesses