Welcome to the forum 910!
There are many sources for information about stamps, their purposes and values. Most collectors probably use the Scott's series of catalogs although they can be expensive if you need the whole set. Of course there are many other similar catalogs.
Some stamp sellers have free catalogs and you can get some information fromvarious Internet sites and even eBay if you know the Scott # of your stamp.
If you can scan or describe some of the stamps in your collection there are folks on this site that would be glad to try to help you also.
Have fun looking and join in on the fun here!