You will likely want to use the Bitmap
] class for saving/retrieving the image.
For the double-click, you'll need to write an event handler. You'll more than likely want to write a single handler that determines the row (such as just making use of the row's click event) and then use information about the row that was clicked to figure out which image to display.
For the image control, just set the source to the image that they've selected. There's no magic there.