A good place to start with identifying your stamps is here (a visual identifier). In my opinion there is no need to spend a money on catalogs for now, you can spend a week or two learning what you need to know online for free.
http://stampsmarter.com/1847usa/1847Home.htmlMost of the stamps that are shown above were workhorses of their era with millions (or even billions) printed. There are some less common varieties and hobbyists enjoy hunting them.
Don