Just to explain the complexity of those manuals, I'll give you a few pointers.
Imagine having to use those every day! That's where I live!
Problem number one, in 1998 GM began using electronic service information, I think at the time of release it was called "SI 2000".
(since then they have dropped the 2000 and now want to call it eSI, but we are all resisting because of an "ESI" experiment gone wrong in the late 90s)
I just call it SI.
With that in mind know that the '97 and back manuals were a dream to use. Information was organized in such a way that I could literally drop the manual and have it fall open to the page I needed!
In 98 with the switch to electronic Service Information they slightly reorganized the information to a "computer friendly format".
Those places where it says "refer to xxxx" are actually hyperlinks on html coded pages that let us click there and go right to the document we need. Not so handy in book form is it?
Over the years I have grown accustomed to using the computerized version but it has taught me where to find things in the paper manuals in the event of a power outage
The first thing you have to get used to is WHERE to find the information you are looking for. The two keys are knowing how the sections are broken down and remembering that GM engineers like to arrange information based on "what something is connected to".
There are I think 10 sections in the manual. Look in the very front of book number one and it will give you a general overview of the main sections. From there you have to learn what system is in what section.
The next part is you have to figure out subsections or "what it's connected to". If you want to find information on something like the inside rear view mirror, you'd look under "stationary glass". And if you want the outside rear view mirrors or the power windows you'd look under "doors" in body and accessories.
Body and accessories is the largest and hardest to use section, Engine is a close second but they break it down a little better.
If you have major problems let me know and I'll guide you a bit.
HTH.