The following artists have periodic and ongoing workshops & classes
Lorin Willey http://www.loricaartworks.com/index.php/artists/88-lorin-willey.html
Tom Nachreiner http://www.tomnachreiner.com/index.html
Ken Bronikowski http://www.finelinedesignsgallery.com/artists/KenBronikowski.html
Art & Soul Gallery http://www.artandsoul-gallery.com/events.html
Milwaukee Sketch Club is a group of artists who enjoy sketching and painting of models with an occasional artist demo or critique