One thing I've learned is that Inside Macintosh is just the primer. It may look like all you need - it lists all the Toolbox functions and how they work, and walks you through how things ought to fit together!
But in reality to make anything beyond TeachText you need to read: every Technote, every Q&A, skim every relevant sample code, every Snippet, and also read every issue of develop.
Then you can start to approach being able to attempt to do something!
And you also have to be able to apply the later content to the former, since after PowerPC came along and everything needed UPPs, none of that was ever documented aside from the initial "BTW you need to use UPPs now".
To use any old documentation you have to manually open the header files and figure out which UPP allocate to use here (oh I'm sure I just missed a tech note somewhere, or an issue of develop).
Goes both ways too - good luck figuring out basic QD after color QD came out!
Karl Baron