Magic the Gathering cards value help

My boyfriend won the magic card tournament in Brisbane years and years ago. He has stacks and stack and stacks of magic cards, probably in the thousands. It's taking up drawers and annoying me!

Just wondering, how do I find ou the value of each card, understanding of course that I know nothing about magic cards, so which set/collection/deck or whatever they are from i'm not sure. Is there was a way to tell the difference between an alpha common and beta (that's the only two terms I have heard of, but don't know what it means). It would be great if I could just find out the value, do a bloody spring clean, pile each of the same card into different piles and just get him to sell some (hopefully most). Any help would be much appreciated

I'm an evil girlfriend, I know.