This is a quite technical introduction to creating works of art on fabric. There have been guides to painting on silk and other materials before, but a lot of them have been for the general market and fairly superficial in their coverage. What’s offered here is most definitely aimed at the more committed practitioner and that makes it something I’m not completely qualified to comment on.
Going through it, it appears to be well laid-out and comprehensive and I guess that, if you’re coming fresh to the subject, you’ll find plenty here to get and keep you going. If you have more experience, then only you can say whether the coverage offers enough detail for you.