The NEC book is over 900 pages long and here is a quick guide to the layout of the book. Don't get confused by the layout of the NEC; it's composed of Chapters, Articles, Sections, Sub Sections, etc. In reality if you follow the basic layout you are golden. Here is a quick breakdown of the Chapters and Articles within that Chapter.
Chapters. Chapters are major subdivisions of the NEC that cover broad areas and are divided into articles. Chapters shall be organized as follows:
Chapter 1 General Article 100 — Definitions Article 110 — Requirements for Electrical Installations
Chapter 2 Wiring and Protection Articles 200 – 299
Chapter 3 Wiring Methods and Materials Articles 300 – 399
Chapter 4 Equipment for General Use Articles 400 – 499
Chapter 5 Special Occupancies Articles 500 – 599
Chapter 6 Special Equipment Articles 600 – 699
Chapter 7 Special Conditions Articles 700 – 799
Chapter 8 Communications Systems Articles 800 – 899
Chapter 9 Tables
Article 498 Future Equipment
498.1 – 498.6
II. Disconnecting Means
498.10 – 498.24
III. Branch-Circuit Conductors
498.50 – 498.58
IV. Provisions for Combination Loads
498.100 – 498.110
210.12 Arc-Fault Circuit-Interrupter Protection.
(A) Dwelling Units. All 120-volt, single phase, 15- and 20-ampere branch circuits supplying outlets installed in dwelling unit family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, or 12 similar rooms or areas shall be protected by a listed arc-fault circuit interrupter, combination-type, installed to provide protection of the branch circuit.
Although opening the book may cause more anxiety and frustration than glee, don't neglect the first 10 pages of the book. There lies the map inside the Table of Contents. Tag, mark and highlight the table of contents, we strongly recommend all of our students to favor the table of contents over the index in the back. Learn the layout and you'll have a head start over index-users.