Norton utilities ver 6.1 of 91, and especially the manuals
accompanying it was a tremendous help in learning and understanding
how DOS works and how to manipulate it. Does anybody know of a similar
program how windows 95 and\or98 work and how they can be manipulated?

Not that I am aware of (I still use Norton Utilities 8.0 and norton
commander 4.0) and haven't found a comparable set of tools yet (a
mulititude of seperate utitilities are out there so I pretty much
build my own set of tools)

try the following 
Disk Keeper    Sort of like Speedisk
Ultra Edit     Sort of like DiskEdit/File Edit
Belarc Advisor Sort of like the info tool 
Win Nc 3000    Sort of like Nortom Commander
Registry Checkup A generic registry checking tool 
Future Mark PC Mark  A generic benchmark tool

they can all be found at www.download.com