A simple free opening editor? 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 fen and the pgn of the game.

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.