I love looking through this book!
This book focuses on micro crochet which uses very thin yarn or even thread. However, any weight can be used to make the motifs using an appropriate sized hook for the yarn. I have already made two different leaf patterns in the book using an E size hook with weight 3 yarn. I find the patterns easy to follow. Each motif has a photo of the finished piece, text explanation, and crochet stitch diagram. I typically go straight to the diagrams and when I wasn't sure what was happening, I found the text was enough to figure it out.
I will take the time to say, this book uses UK terms when I am used to US terms, but there is very easy to understand table of UK term, US term, and then the diagram stitch symbol in the back of the book to help you out.