The stamp shown were the workhorses of the era and printed in the millions. Due to the long production runs, there were a number of running changes made to the stamp perforations over time and these are now assigned different catalog numbers. The overwhelming majority of stamp with this design are worth only pennies; but collector sometimes enjoy hunting for the less common varieties. You can learn more about your stamp here http://stampsmarter.com/1847usa/was...ankmain.html
The site linked above also has every US stamp listed, plenty of 'How To' to get started, and a good Illustrated Glossary' to lookup any unknown terminology.