Instructions
Examine your stamp to see where it is from. The stamp should have the name of the country that it came from written somewhere on it.
Locate the face value of the stamp by looking at the top right corner of the stamp. This will tell you what the stamp was originally valued at when it first came out.
Examine the stamp for watermarks. These watermarks can help identify the stamp.
Examine the stamp grade. Was the stamp printed so that it was properly centered? The stamp grade will help determine the worth of the stamp.
Research the stamp by looking it up in a stamp catalog on the Internet. One resource that allows you to look up stamp information is "The International Society of Worldwide Stamp Collectors" website.
Check the stamp for damage and wear. If a stamp has some damage such as a rip or pen mark, the stamp will not be worth as much as a stamp in perfect condition.