The starting point for many new collectors, is to ask family and friends to save stamps from their incoming mail. Although the stamps received by major businesses, and those kept by elderly relatives, may be of international and historical interest, the stamps received from family members are often of the definitive sort. Definitives seem mundane but, considering their variety of colours, watermarks, paper differences, perforations and printing errors, they can fill many pages in a collection. Introducing either variety or specific focus to a collection can require the purchasing of stamps, either from a dealer or online. Large numbers of relatively recent stamps, often still attached to fragments or envelopes, may be obtained cheaply and easily. Rare and old stamps can also be easily obtained from similar sources, with costs extending far beyond the means of all but a tiny minority of collectors.
Duplicate stamps are the stamps that a collector already has, and are therefore not required to fill a gap in a collection. Duplicate stamps can be sold or traded, so they are an important medium of exchange among collectors.
Many stamp dealers now sell their merchandise over the Internet, while others still have neighborhood stamp shops, which are one of the best resources for beginning and intermediate collectors. Some dealers also jointly set up week-end stamp markets called "Bourses" that move around a region from week to week. They also meet collectors at regional exhibitions and stamp shows.
 Collecting specialties
A complete worldwide collection would be enormous, running to thousands of volumes, and incredibly expensive to acquire; many consider that Count Ferrary's collection at the beginning of the 20th century was the most complete ever formed. So many collectors limit their scope, such as to particular countries, time periods, depicted subjects (called "topicals") or types of stamps.
Some of the more popular collecting areas include:
Postage stamps - particular countries and/or time periods
Definitive stamps - the most common type of stamps
Commemorative stamps - stamps to commemorate events, anniversaries etc., on sale for a limited time. Commemorative stamps are available at a stamp dealer.
Pictorials - stamps printed with images of a country's scenery or lifestyle.
Revenue stamps - stamps issued to pay tax in small amounts. Some early stamps had Postage and Revenue printed on them, to indicate that they were acceptable for both uses.
Postal stationery - includes government-issued postal cards, aerograms, letter card, newspaper wrappers, envelopes etc. Interestingly, the earliest postal stationery predates the earliest stamps- the Kingdom of Sardinia issued the first postal letter sheets in 1819 while New South Wales issued the first postal stationery envelope in 1838.
Sheetlets - this is a format that is now issued regularly by postal administrations. Instead of issuing stamps in large sheets of 40 or more stamps, smaller sheetlets with 16 or 20 stamps are issued with a large selvage area which may incorporate part of the stamp design or theme.
Miniature sheet - is very similar to Souvenir sheet, it will be in a form of a sheetlet with a single or a number of stamps embedded in it.
Souvenir sheets - the many postal services sometimes release stamps in a format that look like a sheet with a big picture. Various parts of the picture can be torn out and used as postage stamps. See example with 10 stamps in one picture. (Souvenir sheets should be distinguished from souvenir cards, which are souvenirs of a philatelic meeting or exhibition but are not valid for postage.)
Corner blocks or plate blocks - compose a block of stamps from one of the four corners of the stamp sheet. Collectors usually opt for a block of four stamps, complete with the selvage area which will sometimes have the printing details on it.
Airmail stamps - stamps required for airmail, which was typically more expensive and had special postage rates.
Postage due stamps are special stamp applied by a post office to mail bearing insufficient postage. The stamps were issued in several denominations to make up different amounts due.
Federal Duck Stamps (stamps for duck hunting licenses, mainly U.S. with some other countries such as Canada and New Zealand)
First day covers - (FDCs) - envelopes with stamps attached and canceled on the first day that the stamp was issued. Most modern FDCs bear designs, called "cachets" related to the theme of the stamp issued.
PHQ Cards, these cards are pictorial postcards, issued by the British Post Office Royal Mail, each card shows an enlarged colour reproduction of a commemorative stamp.
First Day Ceremony Programs - these are folders or brochures given out to attendees of the First Day Ceremonies of postage stamps, with historical information on the stamp, a list of speakers, and an attached stamp, canceled on the First Day of Issue. Collectors of "FDCPs" generally prefer their programs autographed by those who spoke at the ceremony.
souvenir pages - with first day cancelled stamps on a page describing all design, printing and issuing details. This is similar to first day covers except that it is done on a printed sheet of paper instead of an envelope, and the specification of the stamp is printed by the official source. See picture of first souvenir page in the US.
Topical - many collectors choose to organize their philatelic collection on the theme of the stamps, covers, or postmarks. Popular topical themes are animals, dogs, cats, butterflies, birds, flowers, art, sports, Olympics, maps, Disney, scouting, space, ships, Americana (topics relating to the US), stamps on stamps, famous people, chess, Chinese new year, and many others.
Cinderellas - stamp-like labels that are not valid for postage
Government issued material associated with postage stamps (e.g., envelopes)
non-stamp items picturing actual postage stamps
non-stamp items picturing stamp-like labels
counterfeit/forged postage stamps (Before purchasing a rare and valuable stamp for which there is any doubt as to authenticity, it is always advisable to obtain an expert's certificate stating that the stamp is authentic. The most prominent stamp expertising organizations in the U.S. are the Philatelic Foundation and the American Philatelic Society.) There are several types of collectible faked postage stamps:
postal counterfeits are produced by criminals for fraudulent use as postage stamps; frequently, these are scarcer than the stamps which they were intended to represent in part because counterfeits are subject to government seizure and selling them may be illegal
forgeries of rare stamps
reprints are produced by government printing offices or private organizations using the plates used to produce the original stamps; stamp catalogues often contain information on how to distinguish reprints from the originals
faked stamps are common stamps which have been altered to resemble rare stamps; examples of such "fakery" include forged overprints, forged cancellations, chemical alterations of a stamp's color, added perforations.
postmarks or postal markings in general
stampless covers - not all postal markings are associated with postage stamps. Prior to the issuance of postage stamps, postmarks were applied to letters at the location where they entered the mails. The markings were either in manuscript or, at larger post offices, were made with handstamps. Many of these handstamps resemble those in use today (a circle containing the location and date of posting). Typically, the amount of postage was written in the upper right hand corner of the letter or package and the word "Paid" added to the amount if the postage was prepaid. However, a majority of letters and packages were sent without prepayment and the recipient was expected to pay the amount written on the letter or package.