Sound Quality of Remastered CD's

Is there a website (or book) that explains the recording process and music industry? The following should give you an idea of the kind of things I'd like to learn. I'm not asking these questions now, just looking for a source of info about this sort of thing...

Thanks
Don

I have bought "remastered" CD's and compared them to the original purchase I made of that CD. In some cases there was a noticeable improvement. In other cases there was an improvement in some ways and it wasn't as good in other ways. In one case I felt the "remaster" was actually worse than the original. I do know that a lot of it has to do with the quality of the original tapes. In some cases there isn't much room for improvement, such as with the Beatles recordings. BTW I listen to pop/rock, not classical. It seems that the quality of the recordings/releases is really a mixed bag in the world of pop/rock.

Is there really something to this idea of "remastering"? Aren't all CD's by their nature remastered?

What about "imports"? Better sound quality?

Is there a difference between Columbia "club" releases and the originals - in other words, are Columbia club releases of lesser sound quality?

Can I know which remaster releases to avoid and which ones to buy simply by knowing the label releasing it?

etc, etc, etc.