I've been reading CAP 413 but it's a little dry
You should have seen it when I learned R/T!
Sadly I think that some people seem to think that listening to ATC on the web is some sort of security threat and most of the streams that were available look like they're dead. Technically it's probably illegal to stream RT in most places anyway but try Googling "live ATC" and you might find the odd link that works.