Collecting stamps has always been a rather overlooked hobby. Nevertheless, I have been casually collecting stamps since 2012. Recently, however, I have started taking the hobby more seriously and have learned quite a bit.
The first thing I ever learned about stamp collecting is to talk to the workers at your local post office because they can be valuable resources when you start collecting. I got the first half of my collection from a worker at my hometown's post office who knew I had started collecting. A man had found his father's collection in his attic and was wanting to get rid of it so he gave it to the postal worker who saved it for me the next time my mom went to the post office.
Another big thing you'll want to do when you start is get stamp books. These books have rows of clear pockets that hold and protect your stamps and make it very easy to organize your collection. I have two books, divided into U.S. stamps and foreign stamps, but if you feel like being very organized, you can get stamp albums which cover certain countries and show you what stamps to put in them.
The biggest tip I could possibly give is this: go to a lot of flea markets. The majority of my collection has been given to me by people trying to get rid of their families' collections, but in order to keep my collection alive and growing, I have found flea markets are a great way to find stamps. Through flea markets I have found the most interesting pieces of my collection including stamps from WWII era Germany and a collection of first edition U.S. postage envelopes.
All-in-all, stamp collecting is a lot more fun than one would think. With a little bit of work you can start collecting too. Who knows what you might find?