Attempt at a quick overview:
1: Read Only Mode
- Will play the movie back without changing input.
- Loading a savestate from the movie will fast forward/rewind to that point.
2: Recording Mode (Not Read Only.)
- Loading a savestate from the movie will start recording from that point.
- Wherever the movie is stopped, that is where the input file will be cut off.
- You can lose progress if you hit movie stop if you don't stop at your furthest progress.
-You should always hit movie stop at the final frame before you quit/close or the input file may not stop at the latest point.
-In either mode, pressing shift+8 will switch to the other mode.
-Make backups often if you are just getting started, it's pretty easy to accidentally overwrite progress.
- Make sure you have our versions of the emulators you can get at
http://www.bluetoaster.net/emu/all.htm
Start with FCEUX or SNES9x (or possible Gens), they are the most stable.