What other lifting books do you consider essential?
The Complete Keys to Progress by John McCallum. This is actually a bunch of articles from strength and health magazine written by John McCallum back in the late 60's and early 70"s. Really it is one of the greatest collections of basic solid training information.
Rock Iron Steel by Steve Justa. One of the best functional training books I have ever read. There are more ideas there than I can count. It is the opposite of scientific. So if you are a science geek don't bother. From a practical training standpoint, it is brilliant.
Dinosaur Training by Brooks Kubik. Pretty much anything you want to know about odd object training.
Power by Paul / Weights and Sports both by Paul Anderson. If you want strength training advice, why not get it from one of the strongest ever.
Kaz Quest #1 and #2 by Bill Kazmaier. These are training manuals written back in 1981. Once again, learn from the best. Kaz has also maintained his strength longer, without serous injury, than just about every other strength athlete out there. Which is good in and of itself.
Here are some for the science geeks.
Science and Practice of Strength Training by Vladimir Zatsiorsky. I re-read this book every year. As I learn more I find that what I got from reading it the first time is much different than what I got from it the last time. A great book to learn to look at the same information from different perspectives every time.
Supertraining by Mel Siff. Just like the above book. I have every edition from the 1st through the 6th. Every one is worth re-reading over and over again.
Facts and Fallacies of Fitness also by Mel Siff. A very good book about exposing different myths and beliefs of training.
The above is by no means an exhaustive list. They are just the top of my list, and are the best group of books to date that will give a well rounded education into the strength training world.