A few key evaluation resources:
American Evaluation Association www.eval.org
University of Wisconsin Extension http://www.uwex.edu/ces/pdande/        
National Science Foundation's (NSF) On-line Evaluation Resources Library
http://oerl.sri.com      
Center for Disease Control and Prevention (CDC) Evaluation Working Group
http://www.cdc.gov/eval    

Some cultural diversity resources:    
General Office of Minority Health (federal)  http://www.omhrc.gov      
Office of Women's Health (federal) http://www.4women.gov      
Advocates for Youth http://www.advocatesforyouth.org      
Kaiser Foundation Minority Health Links http://www.kaisernetwork.org/ref_links/reflinks_pol_minority.cfm    

Specific Communities (each has great Links section)    
Asian/Pacific Islander
Asian and Pacific Islander American Health Forum
http://www.apiahf.org

African American/Black
National Medical Association
http://www.nmanet.org/
Black Women's Health Imperative
http://www.blackwomenshealth.org

Indigenous/American Indian
National Indian Health Board
http://www.nihb.org/
Urban Indian Health Institute
http://www.uihi.org/

 Latino/Hispanic
National Alliance for Hispanic Health
http://www.hispanichealth.org/
   
Lesbian, Gay, Bisexual, Transgender National LGBT Health Network
http://www.lgbthealth.net/stage

Low-Income, Uninsured Commonwealth Foundation
http://www.cmwf.org/