The title of this book is actually Knitting Handbook: 8 Schools of Modular Knitting. But I kind of figured that the first part kind of goes without saying.
Anyway. The title pretty accurately describes what you are getting with this book. Vivian Hoxbro breaks down modular knitting into 8 separate styles of schools: stripes, squares, tri-squares, right angles, staircases, zigzags, shells, and circles. For each section, there is an explanation of how to work this type of modular knitting, complete with detailed diagrams. Then there are a couple of patterns for each.
There are one or two garment or accessory patterns per section, and many sections also have a pillow pattern, which is a nice, low-stakes way to try out the techniques.
A word of caution about the garment patterns though – these do not come in a range of sizes. Each garment is written out for one, or at most two sizes, sometimes with some vague directions for enlarging if necessary.
But even with that consideration – this book is a great overview of different types of modular knitting, and well worth picking up if you are interested in these techniques!