This book is great. It contains very useful information. The focus is on why and then the how just happens. The structure of each stitch is described; knit, purl, m1l, k2tog, etc, and then there is information about how to improve each stitch. There is information on joining a new ball (always at the start of a row? maybe not), stitching pieces together, casting on and off, and shaping.
There is a great discussion on gauge and why we should all be knitting a swatch and then how to use your swatch to modify the pattern to suit your gauge.
I bought the Kindle version, but on my Kindle Oasis, the images were missing. However, when I used the Kindle app on my Ipad the images were there. Just something to be aware of when purchasing the e-book.
It is definitely something I will refer to in the future.