Well Sporting Lad, no one seemed to understand the gist of your question, which I take it as you wanting, as you said, a 101 course/read on reloading, and not hours and hours of reading huge manuals.
At the time you started shooting you could have had your choice of several 101 pamphlets of reloading.
The one I chose was the Norma Gunbugs Guide, a total of 25 pages, including all the rifle loading charts. Everything one needed to know on how to reload your rifle ammunition to very good efficiency and how to stay safe in doing it, was in that little reloading guide. When the huge manuals started coming out, I think in the 1970s, I never bothered to get one, thus the only real reloading manual I ever had was my little Norma Gunbug Guide.
You could also walk into any gun store and get a loading chart, showing loads, usually from powder manufacturers.
Every loading chart was the same, in that it showed the type of powder to use with various weight bullets in the various rifle calibres and the charge weight of the powder to use.
In short, they didn't state what type of primer to use, or the COAL, or any different powder charges for different bullet, just went by weights, or any starting loads of powder, but most of the charts stated you should start a little lighter and work up.
Once upon a time life was simple!
