I got this book after browsing through the author's well-known website for modular origami. It's a very nice book explaining how to make great looking modular balls. The diagrams are very clear and well described with pictures showing how the modular unit should look like in each step. Being just over an year old in the origami world, I got stumped a couple of times but seeing the diagram of the next step helped me figure out the fold. All I needed was a little bit of practice and a bit more patience. For beginners like me, it's a good practice to make one unit using a printer paper and understand all the steps. Also, I recommend reading the 'Homogeneous Color Tiling' section of the book if one is using multiple colors for making a model.
I believe even a beginner, after getting a bit familiar with the basic origami diagrams, can fold the models in the book as there are no complex folds involved. I highly recommend this book. And if you are into polyhedra and floral models, it is a must.