This document provides guidance on writing effective business letters. It discusses the key components of a business letter, including the letterhead, date, inside address, salutation, body, complimentary close, signature, and other closing elements. It also describes different types of business letters for various purposes like inquiries, orders, complaints, and more. Finally, it offers tips for an effective writing style using the "seven C's of communication" - completeness, conciseness, consideration, concreteness, clarity, courtesy, and correctness. The overall document serves as a comprehensive guide to crafting formal business correspondence.