
Mattkoz!
There are lots of people here who know lots of good stuff if you ever need an answer to a question.
In the USA the book(s) are the Scott catalogs (6 volumes now-a-days), usually available in local libraries in the reference section or on the shelves (if not borrowed).
Other countries use different named catalogs but most are the same regards year of issue and pics of the stamps and other information to help you.
There are some good resources online if you wish to look around.
There are lots of references to serach for on here in the forums also to great sites (depending on which country stamps are from, or what area of interest you wish to look for (cancellations, covers (envelopes), special marking, themes, topics, etc, etc.)).
Scott now also has a catalog just for world stamps listed before 1940 (one book).
Doug