This lesson from Purdue's online writing lab details both the parts of a business letter and the various formats for one, including block, modified block, and semi-block. Great resource for getting started writing a professional letter.

A site that lists the most important parts of a business letter. Very detailed. Also includes labeled samples of how an appropriate business letter should look.

[Free Registration/Login Required] This flipchart explains the basic parts of a business letter.

In this lesson plan students learn about the parts of a business letter and write letters to their favorite restaurants thanking them for their service. The letters are edited and then mailed.