http://vendornet.state.wi.us/vendornet/default.asp
State of Wisconsin - Bureau of Procurement - VendorNet provides easy access to a wide variety of information of interest to vendors who wish to provide goods and services to the state as well as state agencies and municipalities. VendorNet does not provide information on highway or construction projects.

http://vendornet.state.wi.us/vendornet/procman/index.asp
State Procurement Manual - guide to statewide policies and procedures for obtaining materials, supplies, equipment, contractual services and all other items of a consumable nature.

http://vendornet.state.wi.us/vendornet/vguide/index.asp
Vendor's Guide: Frequently Asked Questions About Doing Business with the State of Wisconsin

http://www.doa.wi.gov
Department of Administration

http://wisbuild.doa.state.wi.us/dfd/dfd_reports/bid_list_public.asp
Electronic listing of Department of Administration construction projects

http://www.dot.wisconsin.gov/
Department of Transportation

http://www.dot.wisconsin.gov/business/index.htm
Wisconsin Department of Transportation - Doing Business