Much of this material can be found on the Internet if you know where to look for it. But if you like having a book to read through and consult periodically, this is a terrific resource. What works well about it as a self-coaching guide is that it provides information about how to figure out your own ideal pacing for easy runs, threshold runs (i.e., tempo runs), and hard runs (intervals/repetitions).
If you want to get faster at running, this is one book you should definitely consider getting.
Around the same time, I also bought a used copy of The Self-Coached Runner by Allan Lawrence and Mark Scheid. In format, this is similar to the Daniels Running Formula, but not quite as technically detailed. In some ways, The Self-Coached Runner is easier to use, because it’s got specific training plans based on race distance and desired time goals.
For example, let’s say you’re a 10K runner. It’s got sections on how to train to run a 60 minute 10K, a 50 minute 10K, a 45 minute 10K, a 42:30 10K, a 40 minute 10K, and so on. Each one of those will provide a weekly training plan, broken up (like Daniels Running Formula) into long slow runs, interval repetitions, and so on.
The Self-Coached Runner is out of print as far as I know, but Amazon has plenty of used copies available at fairly cheap prices. Between the two, I personally refer back more to the Daniels Running Formula, but that may be because the charts and details appeal to my math/science side.
(Related: I previously posted some short reviews of a bunch of running-related books here.)