Guide to Researching the History & Intent of WI Administrative Rules

The latest InsideTrack from the State Bar of Wisconsin has an excellent guide on Investigating Wisconsin Administrative Rules.
Author, Bev Butula writes:

Many issues we research center around the rules established by administrative agencies. It is often beneficial to gather background information, reports, and analysis similar to a legislative history when investigating a specific rule. This article highlights a few websites to assist in collecting relevant information on recent and pending Wisconsin administrative rules.