The FASB offers tutorials and help on the Codification.

CPA Jeff Sailor has two free tutorials on YouTube

• Part 1 includes Codification structure and how to use it
• Part 2 describes Codification research options

Extensive guide, with exercises, is designed for learning more about the Professional View of the Codification.

The American Institute of CPAs (AICPA) offers a PowerPoint slide show about the Codification,  to help users with the organization of the Codification and its contents.

Guide offered by the accounting firm PWC

On July 1, 2009, the Financial Accounting Standards Board (the FASB), approved the Accounting Standards Codification (ASC) as "the single source of authoritative U.S. accounting and reporting standards, other than guidance issued by the Securities and Exchange Commission (the SEC)."

The Codification superseded (replaced) all then-existing SEC accounting and reporting standards by reorganizing the existing authoritative literature.

Now, only one level of authoritative U.S. GAAP exists, other than guidance issued by the Securities and Exchange Commission (SEC). All other literature is non-authoritative.

The FASB Accounting Standards Codification (ASC) reorganizes accounting literature.

In addition to General Principles (Topic 105), offering an explanation of Generally Accepted Accounting Principles (GAAP), 

the  Seven financial accounting and reporting categories, which are numbered, are:

• Presentation (Topics 205 through 280)
• Assets (Topics 305 through 360)
• Liabilities  (Topics 405 through 480)
• Equity (Topic 505)
• Revenue (Topic 605)
• Expenses (Topics 705 through 740)
• Broad transactions (Topics 805 through 860)

•  Industry Category  (Topics 905 through 944) contains specific industry guidance.

Also:

• About the Codification by the FASB provides more detailed information about the Codification's goals and organization.
• Notice to Constituents provides information on the Codification structure, style and history.

•  Master Glossary provides definitions of terms

• Other Sources includes accounting standards updates, proposed accounting standards, other exposure documents, Pre-Codification Standards and Maintenance.

The seven categories have topics, and the topics have subtopics.

• If needed, subtopics are divided into sections, which are numbered consistently across all subtopics.
• Sections provide the actual accounting guidance.

A "SEC Section" is included for topics that are affected by SEC regulations.

The subtopic Capital Leases offers an example of the organization:

Toerner, M. C. (2009). A guide to using the Accounting Standards Codification. The CPA Journal, 79(2), 20-25. Toerner is a CPA and an accounting professor.

Ford, C.O. and Thomas, C. William. (2008). Test-driving the Codification, Journal of Accountancy. 206(2), 62+.  The authors are CPAs and accounting professors.