Wumkes - Stads- en dorpskroniek van Friesland
Digital Sources: http://geneaknowhow.net/digi/bronnen.html
Old Frisian maps, clickable: http://www.rabbel.nl/friesland.html#mapold
History of the Frisian People: http://www.boudicca.de/frisian1.htm
Rulers of Frisia: http://www.theroyalforums.com/forums/f160/the-rulers-of-frisia-friesland-18685.html
wapens: http://historie.buwalda.nl/wapens.htm
Frisian aristocracy (adel) in Dutch: http://www2.tresoar.nl/digicollectie/object.php?object=198
Bonninga: http://www.simonwierstra.nl/bonninga.htm
Broer Bonninga: http://www.kuijpers-zijlstra.nl/genealogie/ypma/ypma_c/bonning.html
Bonninga stins: http://sites.google.com/site/stinsensneek/loenga/bonningastins
Haring Harinxma: http://en.wikipedia.org/wiki/Haring_Harinxma
Haringxma State: http://sites.google.com/site/stinsensneek/loenga/harinxma-state
Donia Huis: http://sites.google.com/site/stinsensneek/nijland/donia-huis
Grutte Pier: http://tripatlas.com/Grutte_Pier

Interesting family sites:
Familie Holkema website: http://www.holkema.net/
Families Langenberg en Laagland http://langenberg-laagland.com/
Familie Boersma http://gb129.tripod.com/boersmaped.htm
More to come!