I read this book about a decade ago. I recall it being a decent introduction to backpacking with good illustrations and so forth. However, it certainly was not nearly as authoritative as The Complete Walker
by Colin Fletcher (with the 4th edition co-authored with Chip Rawlins.
For a brief, well-illustrated intro book on backpacking, one of my favorites is Allen and Mike's Really Cool Backpacking Book
For a great related lightweight option (from Don Ladigan with more of Mike Clelland's great artwork), check out Lighten Up!
For less time than Townsend requires, you get a solid, very entertaining backpacking primer.