Reference Frames

Sorry if this question is too basic but I am having questions about plate solving from a reference frame.

I use a ccd camera on an AP 900 mount and SGP works fine with my equipment. Since I have a permanent observatory with an internet connection, I have chosen Astronmy.net as my plate solver. The solver works fine if I populate the target data from my astro-bin images but, I want to be able to center on a target from any .fit image I may have in my computer.

1. Does the reference .FIT image have to be taken with SGP? If it does, how do I acquire it and where should I save it?
2. How do I tell SGP to populate the image position from the reference frame?

Thanks for any help. I would just use astro-bin images but I have a limit on how many of those I can upload. When I tried using someone's else image, the scope slewed to never never land.