Some helpful resources:

http://www.lynda.com

http://www.istockphoto.com

http://www.hitchcockprinting.com

http://www.hnfoto.com

http://www.usagraphicdesigner.com

...And client links:

http://www.soulsticeyoga.com

http://www.paneloc.com

http://www.ccarc.com

http://www.uconnrd.com

http://www.farmingtonfarms.com

http://www.durhamfair.com