I think if you start at https://en.wikipedia.org/wiki/Radiation you'll find everything you need. It's not all in a single linear article, but that's mostly a strength of the Wikipedia style.
That's the point, though. Having it curated and written by experts puts them in control of what direction you go. Realistically, I could click through the radiation article on wikipedia, and may be exposed to what I need to know, but I also could just wander down a rabbit hole of useless information.
That's the entire point. I'm not the expert. Nor am I able to even understand the basics of which direction to read/learn - that's what the expert curators are for.
