This document provides guidance on conducting audits according to basic auditing assumptions and definitions. It outlines the responsibilities of auditors and auditees, as well as qualifications needed by auditors. Guidelines are provided for audit quality assurance, working papers, lead auditor responsibilities, interview tips, audit plans, reports, techniques for understanding quality management systems, auditor attributes, inquiry categories, interview considerations, principles of audit reporting, process requirements, and sampling. The document describes elements of a successful audit from planning through closure.