There is no typical business plan, so there is no one right answer to this question.
Basically, it all depends on the intended use of the plan and its target audience. For instance, an internal strategic plan will be heavy on detail and may include many pages (upwards of 100 or more!) of organizational charts, timelines, etc. Whereas, an external start-up plan being presented to a banker needs to be less wordy, while still being effective and should be no more than 20 to 30 pages in length.
When it comes to the Executive Summary, you should be able to summarize the key points of your business plan in less than three pages. This is a must!
Crystal