how to download emulators and roms

ya so this is my first time downloading an emulator and rom and i was wondering can some one help me cause i have no clue and Ive seen a few videos on how to but i just screwed up can some one help me with how to download the emulator and rom (i want to use the no$gba emulator and play digimon world dusk)

Download the full package of no$gba from here.
http://www.mediafire.com/download.php?0tmrvozm0gmafter that, download the rom that you wanted to play.
Extract it, and then run the no$zoomer that comes with the package.
and then load the game.Go here for a tutorial.
http://forum.romulation.net/index.php?topic=31241.0