Pennsylvania Department of Revenue
http://www.revenue.state.pa.us/portal/server.pt/community/revenue_home/10648
Internal Revenue Service
http://www.irs.gov/
W-9 Forms for Sub-Contractors
http://www.irs.gov/pub/irs-pdf/fw9.pdf
W-4 Form to be filled out by your employees
http://www.irs.gov/pub/irs-pdf/fw4.pdf
