Steiner's Sheepshead - A weekly tally of results from an ongoing Madison, Wisconsin game begun in 1996. - http://sheeps.pauer.us/
Schafkopf Group - The rules, tactics and variations for the Sheepshead/Skat/Doppelkopf/Schafkopf game family. - http://www.pagat.com/schafk/
International Skat Players Association - Organizes tournaments and promotes the game worldwide, with local chapters in a dozen countries. - http://www.ispaworld.org/
Sheepshead Central - News, tournament updates, event photos, online polls and an active message board. - http://groups.yahoo.com/group/sheepshead_central/
Schafskopf - Rules and strategy for the three-handed game variety. - http://www.robreid.com/schafskopf/
Sheepshead Association - Free group offering game rules, glossary, history, and related resources, with tournament and open play news. - http://www.sheepshead.org/