Hi Calico,
It may have been me :-). For me the first 5 chapters ( if they are same in the new edition as mine, the ones by Darwyn Peachey and Steve Worley anyway ) are the most important and the ones I got the most out of. The other stuff is interesting as well, but if you want the basics on how to create effects using function networks in TG2 there is a lot of good stuff in those first chapters. I'm not sure there is a better introduction to it. It's how I learnt shader writing, pretty much.
TU, for me the book is not so much "theoretical/technical background" but rather "how to do this stuff". It's hands on. Of course in TG2 we have a number of the functions described available as nodes so you don't have to build things entirely from the ground up, but understanding what they do and how they do it will make it easier to figure out how to achieve the results you want.
Ok, so you do need to know a bit of maths, but it's not impossible. I've never been great at maths myself. You can go a long way just understanding the concepts and not the details. If you can get the concepts down you can at least start to imagine how to put things together.
Of course you do need to figure out how to put things together in TG2 using the nodes and all that, the book doesn't describe how to work with TG2. If you can figure out shaders you can figure out that though, and vice versa :-).
Regards,
Jo