Welcome!
You have a neat collection of family heirlooms. While you never know, chances are greatest that there is not any rare stamps among them. But learning about these stamps, and organizing them for future generations of your family is definitely a worthwhile pursuit. Please also note that stamps are like many other things, condition is quite meaningful. Most of the items you show have some significant condition issues.
With this all said, you might start with checking out the Stamp Smarter website
http://www.stampsmarter.com/1847usa...ankmain.htmlMany times there can be subtle differences in stamps that look the same. A stamp can have the same design but the perforations or watermark may be different. This occurs because many times there were running changes in the stamp production over the many years the stamps were in use. It is not uncommon to have significant value differences based upon these attributes.
I would also add that for the time being do not remove any stamps from the covers and keep anything in the envelope (contents) together until you become more knowledgeable.
There is also a US catalog, called Scott Specialize US Catalog, that you may want to reference at some point. Catalogs are not cheap, but you can often find them at your local library. But for now you can begin learning by using the Stamp Smarter site and asking questions of the kind folks in this community.
Don