After getting the background image into place and saving - closing and coming back the background image is gone. What must I do to keep the background image in place?

 If you are setting the background image using View>Background from the window header, the picture will only display when using the camera view in which it was set. i.e Top, front,side. 

The image location should be saved in the blend file and reload on next opening. If not open the background image panel and check the name and path to the image is correct. If the image cannot be found there will be a message to that effect in the panel.

Touchwood is correct menschtx, the file paths for images have to be preserved.

This is why i usually pack any imported images i am using into the blend file.

You can do this by selecting: File/External Data/Pack into blend file

The image will then be stored inside the blend file.