Numerous resources on the Internet can help you develop policies and even supply sample policies that you can tailor for your organization. Here are four good places to start:
Information Security Policies Made Easy, 9th ed., by Charles Cresson Wood
http://www.informationshield.com
Information Security Policy World
http://www.information-security-policies-and-standards.com
SANS Security Policy Project
http://www.sans.org/resources/policies/
Site Security Handbook
http://www.ietf.org/rfc/rfc2196.txt