Here's some other good resources:

http://www.ncba.coop/abcoop_work.cfm

http://www.ica-group.org/2nd%20Row/FAQs.html

Example Companies:

http://www.belugasoftware.com/overview_s.html

http://www.webcollective.coop/

http://www.isthmuseng.com/aboutus/workerownedcoop/workerownedcoop.aspx

http://www.alvaradostreetbakery.com/coop.html