This is my first book purchase about the subject after library reading; others can be a little thin on why things work scientifically and why various ingredients are used. This book comprehensively covers that aspect, and is reasonably free from cranky or "mother goddess" stuff(!)
Two things others might want to note; it uses obviously American terms (eg. veg. shortening) and measurements and has no resource pages based in Europe; second, some of the ingredients used I have found from simple european research are considered "suspect" to use for skin, eg. borax for it's chemical toxicity and lanolin for it's pesticide residue and allergic reactions (something Tourles mentions but disregards.)So making products diy can be just as confusing as buying them if you want to avoid "nasties" - still, you can just test on yourself instead of animals!
So, as a beginner, I think it's good in that one can almost immediately start simply producing cleanser, toner, lip balm, body scrub, etc. and for anyone else purchasing this book in uk it is good to have the basics in front of you; as soon as you go to online ingredient shops you will discover other recipes and opinions or science about ingredients - I would have done more research anyway because of my own allergy problems.