I am looking for a simple and free opening editor where I can save openings and variations. I know Chess Position Trainer is free, but I am looking for something much more simple.
You can go here: http://www.caissa.com/chess-tools/pgn-editor.php and select the tab "2. Game Moves", then make your moves. The fourth tab will show the
As far as where to store them, create a folder somewhere named openings, and save each different set of fen/pgn as a text file with the output.