Links:

Wisconsin Department of Commerce FAQ:

UDC: http://commerce.wi.gov/SB/SB-UDCProgram.html
Commercial: http://www.commerce.wi.gov/SB/SB-CommercialBuildingsCodeQuestions.html

Forms:

UDC: http://commerce.wi.gov/SB/SB-DivForms.html#one&two
Commercial: http://commerce.wi.gov/SB/SB-DivForms.html#commercial

Codes:

Uniform Dwelling Code UDC
Electrical Code
Plumbing Code
Commercial Building Code

Organizations:

International Code Council ICC: http://www.iccsafe.org/
National Fire Protection Association NFPA: http://www.nfpa.org
Wisconsin Department of Natural Resources: http://www.dnr.state.wi.us
Building Science: http://www.buildingscience.com/
National Electric Code NEC NFPA 70: http://www.nfpa.org
League of Wisconsin Municipalities: http://lwm-info.org