You can subscribe to beckett's online price guide at beckett.com, but I must add that it is extremely useless. magnum_xxxL was correct when he mentioned eBay. Just create an eBay account if you don't have one, search for the card(s) you're looking for, check "completed listings" in the left hand sidebar and hit Go or whatever it says to proceed. It will then show you what the card(s) actually sells for. Beckett is garbage.
I collect basketball cards, but my collection is a bit more updated, as it consists of many autographs and cards with game-used jersey pieces on them. If you take a look in the Sports forum, though, you can see a thread I posted about my key vintage rookie cards.
Glad to see another collector on the TFP. I've been trying to get a collecting forum going on here, but it doesn't seem to have that much support at all.
P.S. I trade with Australians all the time. If you PM me, i can direct you to a trading site that is dedicated to Australian collectors.