I was hoping someone else would answer your question since I was too lazy but here it is:
There's a very easy way to combine the two pictures (you really must combine them for the galleries).
1.
Use Irfanview to open each picture, with the mouse mark a rectangle around the coin, leaving just a little
border. From the menu choose EDIT->CROP SELECTION. Save the images separately.
2.
Then click on IMAGE -> CREATE PANORAMA IMAGE and choose the two picture files. You might want to disable the automatic sorting there under SORT IMAGES, otherwise the result might have the
reverse to the left, which is not how it is usually done. Then click CREATE IMAGE and save the result.
There's a slightly more alaborate process (but not difficult either) that I prefer now and that is much better for irregular coins.
Use GIMP (also free).
I usually do step 1. from above with Irfanview.
Then when I have my two separate pictures. I create a very large new picture in GIMP. I open the
obverse picture in Irfanview, press CTRL+C, go to GIMP and press CTRL-V to insert it. Then I move it to the top left, click SELECTION->SELECT NOTHING (or similar, I'm using the
German version). I then repeat the process with the
reverse picture. I end up with the desired picture with a more or less large
border to the right and on the bottom. I then click on IMAGE->CROP AUTOMATICALLY and save the result as a JPG file (when saving enter "desiredFilename.JPG" as a name, otherwise the program will use another file
type, unsuitable for posting online).
It's really less complicated than it sounds.