You can also download the Nexus Mod Manager, as some modders make their mods specifically to be installed with that one (however, it is not as good or error-free as FOMM, and the Nexus staff basically abandoned it, so I personally am not too fond of it). If you're planning to play Fallout 3 or Fallout: New Vegas with mods, the first think you want to do is download a mod manager called Fallout Mod Manager (or FOMM for short).
