I have this book, and it's not what I'd call a textbook.
It rarely explains how any of it works (you'd be hard pressed to find the formula for a probability distribution function, for instance), so it's just a one-stop collection for a lot of useful tests and the circumstances under which they should be used.
It's less of a textbook, and more of a reference for someone who needs to occasionally work with statistics and can't remember offhand when the T-test is appropriate or the procedures to undergo for a chi-squared test or whatever.