Things You'll Need
Instructions
Join the American Philatelic Society. (APS) For a small membership fee you receive their publication, which gives detailed information about stamps, values, shows where you can purchase stamps and other related information. They also have an in-depth website where you can check their massive library of stamps to find the value of stamps in your collection.
Check Craigslist, the newspaper and local auction places to find people selling collections. Also check listings for estate and garage sales to see if they have stamps available.
Become a member of eBay and check the site often for collections posted for sale. Many times a collector will decide to discontinue a part or all of their collection and offer it for sale in its entirety.
Place an ad on Craigslist or in your local newspaper stating that you are interested in purchasing full collections of stamps. Often someone who is not interested in collecting stamps will inherit a collection from a relative and be interested in selling it.