Payroll
W-4
https://www.irs.gov/pub/irs-pdf/fw4.pdf
I-9
https://www.uscis.gov/sites/default/files/document/forms/i-9-paper-version.pdf
Contractors
W-9
https://www.irs.gov/pub/irs-pdf/fw9.pdf
Government
Internal Revenue Service
https://www.irs.gov/
Social Security Administration
https://www.ssa.gov/bso/bsowelcome.htm
Employment Development Dept
https://www.edd.ca.gov/About_EDD/Employer_Services_Online.htm
Franchise Tax Board
https://www.ftb.ca.gov/
CA Dept of Tax and Fee Admin
https://www.cdtfa.ca.gov/
CA Secretary of State
https://www.sos.ca.gov/