This book will introduce you to the basics of Japanese braiding. There are full step-by-step instructions for each move, followed by pictures of lovely examples to inspire you.
I did not have a marudai, but because her many pictures were quite well thought out, it was easy to see what was necessary, I was able to construct one out of the box my books came from (it needn't be round). Rolls of 25 pennies can be used as bobbins. Emroidery floss doesn't work well, as it is not long enough...one should use embroidery thread on spools for this. <-She does speak of this in the book, but a lot of people buy the tools with the book without being able to read through it first.
The braids one can learn are all made with 8 bobbins. She explains how the colors and patterns can be changed with a change of thread color or thread texture.
If you are thinking of this book to make obijime: These are all basic braids (nothing too fancy), so it is an excellent beginners book...but it will not make the fancier braids you see in most flat obi jime. It will make the braids for round obijime, though.
This book gives clear, simple directions for making or improvising the tools needed. It takes a bit of effort to hold the incomplete work in place and feed in each strand as needed, so the tools really are necessary. You can't just grab a few strings and try the techniques. The tools are easy to put together from common household materials - film canisters, coins, and a few other things - so don't let that put you off.
The braids themselves are presented in beautiful photos, along with clear, complete directions for making each one. The photos also show how one braid can look very different according to the colors and kinds of strands woven together.
It's not something to pick up casually on a rainy day and try with your kid. It takes some preparation, and some practice to get an even result. That is well within reach of the home crafter, though, and well worth the effort.