CCH Business Owner's Toolkit: Building a Successful Marketing Plan
http://www.toolkit.com/small_business_guide/index.aspx#abrn01

Entrepreneur.com: How to Create a Marketing Plan
http://www.entrepreneur.com/marketing/marketingbasics/marketingplan/article43018-1.html

Glossary of 650 marketing terms
http://www.quirks.com/glossary/

How Marketing Plans Work
http://money.howstuffworks.com/marketing-plan.htm

The Write Market: How to Write a Marketing Plan
http://www.thewritemarket.com/marketing-plan.shtml

KnowThis.com: Marketing Virtual Library
Information on market research, strategy, Internet marketing, and marketing plans 
http://knowthis.com/
http://www.knowthis.com/principles-of-marketing-tutorials/how-to-write-a-marketing-plan/Marketing on the Internet

MarketingPower.com: American Marketing Association
Marketing information, articles, products, job notices. Free Registration.
http://www.marketingpower.com/

Mplans.com: Sample Marketing Plans
http://www.mplans.com/spm

SBA: Marketing Your Business
http://www.sba.gov/smallbusinessplanner/manage/index.html

Basic Marketing: BusinessTown.com
http://www.businesstown.com/marketing/index.asp

Rutgers University: Internet Marketing
http://www.libraries.rutgers.edu/rul/rr_gateway/research_guides/busi/imarket.shtml

Rutgers University: Doing Business on the Internet
http://www.libraries.rutgers.edu/rul/rr_gateway/research_guides/busi/ecomm.shtml

Web Marketing Information Center
Provides numerous articles on online marketing
http://www.wilsonweb.com/research/