What is a good website where I can find the value of my Baseball, Basketball, Football, and Hockey cards?

The best source for the prices of sports cards is Beckett monthly publications, but for collegiate cards, I recommend the Beckett online subscription. It is what I use, it is more current, and updates more often. I sell and purchase sports cards on eBay, and I can tell you that they are pretty much dead on as to what value your cards can reach, you can check the ended listings, and do the research there to properly gauge your prices realized.

Now on to collegiate cards, I have noticed that in recent years there has been a market for college football and basketball cards, I have realized some nice prices with these, but I have had them graded in order to do so. Example ( 1990 Penn State Joe Paterno, price $3.00) after grading, the card came back a BGS 9.5, I sold the card for $95.00, just to give you an example. There is a market out there, but you have to make your cards marketable. Of course some cards are just not worth grading, you will have to figure those out for yourself.

Every one want to sell cards and no one wants to buy them. Unless you have some decent rookie cards then they are basically worthless.

I'd look up how much they're going for on Ebay.