I totally agree with you about the awesomeness of the software manuals from the time. The whole aesthetic is so much warmer then it is now.
You should see how amazing the manual for my Amdek monitor is, or the Grappler + graphics card for the Apple // (allows you to print graphics from your Apple // to a dot matrix printer):
https://apple2online.com/web_documents/Orange%20Micro%20Grap...
If you were lucky, other authors may have published books of various quality and you MIGHT be able to but a copy at your book store if you even knew to ask about it.
Or you might connect to knowledgeable people through a bbs or user group to learn some tricks. Magazines helped... a little.
But there simply was a dearth of information as compared to the resources of today.
One only needs to spend about 10 mins on stack overflow to see that much of it is the blind leading the blind, where most of the answers are incomplete, biased, outdated, wrong, etc.
I often envy my friends 10 years younger than me, but at the same time, I am glad I got to experience the small B&M computer shops. I even went to an oldschool computer show at the fairgrounds once... and got ripped off on a tape drive that didn't work with my 286 lol.
Also the joy of buying random obsolete junk at mac frugals/big lots/99 cent stores when they'd get surplus. I got quite a few games that way!
The closest equivalent I can think of is my Asus motherboard. It came in a fancy box with a lot of stickers, and most importantly, a big manual of all of its features. Sure it doesn't give me an in-depth diagram, but it's better than nothing.
I was most disappointed by my newest video card. It came with.. absolutely nothing. I think it may have come with a folded piece of paper about how to install it?! The damn thing cost $500! The cheaper MSI ones come with a friggin comic book with a cute dragon in it!
Edit: The MSI comic book: https://www.geeks3d.com/public/jegx/2018q4/msi/msi-graphics-...
Yah, I don't get it for many things. Windows, should come with a basic users manual on paper. It should include the global keyboard shortcuts in the back too, but it doesn't. I'm not sure anyone at MS could even write them all down at this point.
Besides that, what kills me are all the completely insane things like the xbox (which has a terrible UI) games that come on bluray, but then require internet access before you can start playing so that they can discover they need to download a 10G patch. Its like they said "hey we are going to release this game to retail channels, but we know it doesn't work so the first thing its going to do is call home to download itself" or something equally stupid.