Quick guide to employment laws:
Federal Laws by Number of Employees
Record keeping guidance:
Federal Record Retention Requirements
The Employer Handbook Blog by Eric B. Meyer, Employment Lawer:
https://www.theemployerhandbook.com/
COVID-19 Guidance: Returning to work:
https://www.osha.gov/Publications/OSHA3990.pdf
https://www.cdc.gov/coronavirus/2019-ncov/community/reopen-guidance.html