Know-How Exchange : Strategy

A marketing plan is a written guide to assist you to integrate your total marketing effort.

Good plans include at least some of the following:

analysis of your market
business objectives
key strategies
steps to achieving those objectives
proposed budget
timing

I think that you have to let us know a little bit about why you are asking the question. It seems plausible to assume that since you had the ability to post on a site, that you probably did a simple search for "marketing plan". Do you need clarification about a certain aspect or help in interpreting what you have already read? Without that information it seems difficult to give you any helpful information.