Begin with something that describes the origin of the lesson. For example: This lesson was developed as part of Missouri's eMINTS Project (enhancing Missouri's Instructional Networked Teaching Strategies).

In this second paragraph of the introduction, describe briefly what the lesson is about. Remember, the audience for this document is other teachers, not students. 

Learners
Describe the grade level and course that the lesson is designed to cover. For example: "This lesson is anchored in seventh grade language arts and involves social studies and math to a lesser extent." If the lesson can easily be extended to additional grades and subjects, mention that briefly here as well.

Describe what the learners will need to know prior to beginning this lesson. Limit this description to the most critical skills that could not be picked up on the fly as the lesson is given.

Standards
What will students learn as a result of this lesson? Describe the outcomes succinctly. Use the language of existing standards. For example:

Social Studies Standards Addressed

     Recognize the relationships among the various parts of a nation's
     cultural life. 
     Learn about the mythology, legends, values and beliefs of a
     people. 

Most lessons don't just teach a block of content; they also implicitly teach one or more types of thinking. In addition to describing learning outcomes within traditional subject areas, describe what kind of thinking and communications skills were encouraged by this lesson. Inference-making? Critical thinking? Creative production? Creative problem-solving? Observation and categorization? Comparison? Teamwork? Compromise?