For the background, I personally don't like to see coin images sitting on a cloth. To me it looks very odd. Make the coin's background the same color you expect to crop to (many use white or black) and use paper or something else flat.
For lighting I suspect you will determine that you need two light sources, not just one. But play around with it and see what you can get from the flash.
For lighting I suspect you will determine that you need two light sources, not just one. But play around with it and see what you can get from the flash.




















