Mugening?
That seems like a book about character design, if you want to learn about character desing then any tips are useful to create your own stuff, so yeah, I guess the book would be useful. Although I think you can find the same info in youtube and google about the things to take into account when designing characters/BGs.
I like ABI-torials & BaM for example, he explains stuff pretty well, things to do and what to avoid:
Here's more:
but If you want to learn about coding capcom game characters in mugen then I don't think it will be too useful.