I recently got some items at an auction that I would like to see what they are worth...they are Post Cards all are Dodge cars from the late 50's to early 60's.Mopar stuff...Does anyone know where I might find some information? I assume they are collectors items?

There are collectors of advertising postcards out there, and there are many available on ebay such as This seller

If you were interested in selling them, auction sites may be the way go, to research what similar items are going for. As with any other collectible, value is based mostly on how many are out there, the condition of yours, etc.

I deal in postcards and pre- 1960 cards are very collectable, transport cards being really popular at the moment. ( I sell shipping postcards mainly). There is normally no difference in the price whether they are used or unused but some stamped/postmaked cards give clues to the age of the card. Check out auction sites for guide prices. Like Giz says, it depends on what is being offered at the time. Only offer cards in excellent condition. If they are bent or creased they are mainly worthless. Good luck!

Have a look at this and this