[Broken Glass Can]

In terms of collectables, you don't really need to know all that much if you just follow a few rules:

1) Only buy valuable and rare items (Whether a stamp or a comic book, if it is worth $1000 now, it will hold its value and likely increase)

2) Make sure you buy them without a huge dealer markup (An auction for example) and that they are actively traded (so you can find a buyer when you want one)