Whatever you are initiating the "Save" function as, for instance if you place a button and override the onclick. From there loop through your grid's rows, look for CMSEditableText controls and grab their values and save.
For load, usually webparts have a "Setup_Control" function, otherwise a page_load will suffice for loading in your data. IT's still in it's core an ascx control so you can use the various page lifecycle events to set your values up (onInit, onLoad, etc).
Hope that helps! there's on stacktrace some "Find all controls of this type recursively" out there.