Purdue University
Purdue Engineering/wellhead Protection
This resource describes what well head protection is, what you can do, case studies, why you should care, and related links.
Other
Iepa:wellhead Protection in Community Water Supply Wells
Discusses what wellhead protection is, why it is needed, who is involved, a step by step plan, and a nice diagram of a well and the surrounding area.
Other
Ncdeh: Drinking Water
This site from the North Carolina Department of Environmental Health discusses the impact of Safe Drinking Water Act on wellhead protection, wellhead guidelines, delineation, management, contingency plan, and public involvement.