Here are the settings described: http://www.wiihacks.com/software-bac...-settings.html
You can load back into GX from a game by installing the forwarder dol from the root of your card in priiloader and setting "Return to: Installed File". If this sounds unfamiliar make sure to view the Readmii that the page above links to.
Not sure what you're trying to save ... If you mean is it possible to save state on your Wii games, then no. Each game has its own method of saving within it's contextual menus.