This is edited from the how-to section from the piece I originally wrote for my old Angelfire site around 2005-07. I also saved my how-to posts on numismatism (coin-collecting) and marble collecting, if anyone is that interested in me reposting them here.
1. Read guidebooks, stamp magazines, trade publications, grading books. If possible, try to attend a conference, lecture, show, or convention.
2. You need to know how things are graded, or you risk getting cheated and duped. You don’t want to pay $300 for a very common stamp or trade in a bunch of duplicates for $50 when they’re really worth $160.
3. Uncirculated stamps are worth more. If it’s rare and/or in demand, it won’t matter to a serious collector if it’s been voided by going through the post, but don’t expect to be paid full value for a bunch of cancelled stamps.
4. The ideal way to handle stamps is to pick them up with tweezers or a similar grabbing object (provided it’s not sharp and won’t tear the paper). Dust and body oil devalue them.
5. Stamps shouldn’t be stored in the sunlight. Since they’re really nothing more than delicate thin paper, they can be fragile and are likely to fray easily if not stored and handled correctly. They belong on mounts or in albums. Even an inexpensive spiral notebook works. That’s the state of a big collection my late grandpap gave me. He came across a neighbour burning her recently-deceased husband’s belongings, and he saved the immense stamp collection by saying he had a granddaughter who liked to collect stamps. A lot of them are quite old, and from places that no longer exist, or now have new names.
6. Never try to remove a stamp from an envelope by yourself unless you know what you’re doing. This decreases a stamp’s value. It’s not hard to steam or soak a stamp off, but this isn’t something you want to be doing unless you’re absolutely sure of the correct procedure. It’s the same way you should take a copy of Yesterday…and Today to a professional to have the top layer steamed off if you spot the signs of the butcher cover.
7. The rabbi emeritus at my original shul said it’s important to have a special focus, not to collect every stamp you see. His focus is Judaic stamps, some of which he gave me in spite of my protests that he didn’t need to give away part of his collection.
8. If you know an older philatelist, as I did, nurture that relationship! Your friend might be eager to help you by giving you stamps.
9. If you tell people you’re a philatelist, they might send you letters and postcards with nice stamps.
10. Buy special stamps at the post office. You can also request people send you communications with those stamps.
11. Let those you live with know you’re a philatelist, so they’ll cut out interesting stamps on letters for you.
12. You could find stamps at auctions or antiques stores. They may have old postcards or stamp albums. Older relatives also might have stamps.
13. It’s a good idea to get your collection ensured if you know it’s worth anything.
14. Just because a stamp is old doesn’t automatically guarantee it’s worth much. If you see a lot of duplicates, it means they were very common.
15. Try getting a foreign penpal or writing to friends and relatives abroad.
16. There are over half a million types of stamps today. Unless you’re independently wealthy, there’s no way you can acquire and store them all.
17. Know the basic guidelines for worth. Common stamps are worth two to five cents apiece. Really common stamps (such as flag stamps) are only worth a penny. Mint copies are worth the same price they were when they were originally bought. If it’s rare, even if it’s cancelled, it’ll be worth more. In the late 19th century, stamps were issued in about 20,000-100,000 copies; today there are a hundred million, as well as over a billion Christmas stamps produced each year. Many older stamps were later destroyed.
18. If you come across a string, block, or sheet of stamps, never attempt to pull them apart. This can tear them, and ruin their value. They’re worth more in their original state, since it’s so rare to find an intact strip of stamps from, say, 1883.
19. If it’s foreign and/or old stamps you’re after, your best bet is a collector. You don’t happen into old or foreign stamps on a regular basis.
20. Don’t let yourself get cheated. Some stamp dealers offer common stamps for exorbitant prices, and people who don’t know any better fall for it. Sometimes it’s even incredibly obvious that the most valuable stamps have already been removed from these collections. For example, there was one e-Bay auction advertising 35 old Russian stamps, yet on the side of the scanned stock sheet, there was a Post-It note saying “44 old Russian stamps,” possibly written by the previous owner. That leads one to believe the dealer removed 9 valuable stamps and sold 35 of lesser value. It sold for $10.50 (the opening price was $10), when it was only worth about $2.