USA Payroll has found these web sites to be helpful.

Federal
Internal Revenue Service	www.irs.gov
Social Security Administration	www.ssa.gov
US Department of Labor	www.dol.gov
New Jersey
NJ Division of Taxation	www.state.nj.us/treasury/taxation/
NJ Department of Labor	http://lwd.dol.state.nj.us/
Pennsylvania
PA Department of Revenue	www.revenue.state.pa.us
PA Department of Labor and Industry	www.dli.state.pa.us
Delaware
DE Department of Labor	www.delawareworks.com
Philadelphia
Philadelphia	www.phila.gov