Step 1: Download the Rom (the game file linked on previous page, example: JerryHack1.nes for Jerry's Remix 1)|
Step 2: Download FCEU Ultra and install it. File, Open, Jerryshack1.nes or whatever game hack you downloaded.
Step 3: Go to Configure, then Input. Select which device (probably keyboard if you have no joystick) and input the keys how you want. I generally use Z and X in place of the A and B buttons, Spacebar for Select, and Enter for Start.
That's it! You're ready to play the nintendo game as if you were playing nintendo. Note there are thousands of roms available for download.
If you would like to play full screen, then when the emulator is in the foreground, hold ALT and hit ENTER. Any time you want to undo full screen, hold ALT and hit ENTER again!
If you'd rather play the roms online without downloading them, download just one and choose "open with" on the right menu and
find where you installed your emulator. Now any time you click on a file with the extension "nes" it'll automatically open from
the web. No more downloads!