Baseball Cards Price - I have many different trading cards from my childhood, how do I find their worth?

I have many different trading cards from my childhood, how do I find their worth?

There are baseball, football, star wars, elvis etc... I cant find a good source to get values on these items.

http://www.collectsports.com/
The sports cards: Go to a hobby shop and buy Beckett magazines for the specific sport. They also have a site online, but I haven't found it to be as helpful as their store-bought pricing guide magazines. Other collectibles: Best I can tell you is to do a search on eBay and see if anyone else is selling them and what they're going for.