Here is a listing of websites with some helpful information:
Apicurious: www.api-curious.com
Bee Culture: www.beeculture.com
Bee Informed Partnership beeinformed.org has information from a variety of surveys.
Honey Bee Suite Blog: www.honeybeesuite.com
Kenagy Family Farm: www.kenagyfamilyfarm.com (Cover crop seeds)
Oregon Master Beekeepers Program: http://extension.oregonstate.edu/mb/
Oregon State Beekeepers Association: http://www.orsba.org
OSU Bee Lab: honeybeelab.oregonstate.edu
Scientific Beekeeping by Randy Oliver: scientificbeekeeping.com