First off you need to know the dates. Early catch and release season opens on the first Saturday of January yearly. It runs to the Friday before regular season opens on the first Saturday of May. No live bait is allowed in catch and release season.
Regular season runs through the 15th of October. Many of the regulations have changes. The idea of simplifying this season was thrown out the window. You better look at each stream you plan to harvest fish in because the regulations have changed. For example the special regulations in Richland county were twelve prior to the changes and now there are twenty-three special regulations. This is the case in all the counties for folks that want to harvest trout.
http://lenharris.blogspot.com/2015/12/wisconsins-new-early-trout-season.html