Originally posted by: yukichigai
I've been collecting since Revised. I can give you a hand.
Alpha - Black bordered, no symbol, round corners. (More round than most)
Beta - Black bordered, no symbol.
Unlimited - White bordered. If you see the phrase "tap to <do something>" and it's white bordered w/ no symbol it's definitely Unlimited. Also if you see the cardtypes "Mono Artifact", "Poly Artifact" or "Continuous Artifact".
Revised - Same as Unlimited, though some are reported to be "washed out". Has a tap symbol on certain cards, which looks like a tilted "T" in a circle.
Fourth Edition - Similar to revised, though with smaller copyright text and crisper colors. (EDIT: and 1995 at the bottom, I think)
Fifth Edition - Very small copyright text, also has differently-shaped mana symbols and a new tap symbol. White border seems to be larger on these cards.
Chronicles - Anything with a symbol and a white border. (except for 6th, 7th and 8th editions) I'm sure a lot of those cards you have are Chronicles, not Legends or Antiquities.
Also, Foil cards out of some of the base sets (6th, 7th, 8th) will have a black border.
I'll be able to tell you more when I get home, as I'm at work right now.