Big Walls is the book to start anyone on the road to understanding Aid Climbing. It's written by John Long and John Middendorf with excellent descriptive photos and drawings. The book is broken down into 13 chapters: The Vertical World, Grades and Ratings, Placements, Aid Slings & Weighting Placements, Leading, Following Pitches, Multi-Pitch Routes, Hauling, Multi-Day Routes, Advanced Aid Techniques, First Ascents, Solo Techniques, and Styles and Ethics. There are five appendices: Yosemite Climbs, Gear Checklist, Climbing Areas, Suppliers and Guides. There is also a glossary included.