I do mine in Paint Shop Pro, and I do it just a little differently than the previous poster. This is what I do:
1. Open a 1 in X 1 in New document.
2. Open the picture you want to use, copy and paste it to your 1X1 document as a new layer.
3. Size it to fit, erase background you don't want, etc.
4. From there, you now you have a 1 X 1 inch image, and you don't have to put a border on it if you don't want (although I almost always do.)
5. To add a border, first create a new layer. On the new layer, choose 'ellipse' on the selection tool button. You need to make sure that the fill color is transparent. You can also adjust the width of your border up at the top on the right hand side. Draw you circle. Then, if you need to move it or change the size, go up to the menu bar and choose the edit mode (took me forever to figure out that was there, I just kept totally redrawing the circle---drove me crazy!! lol) Make sure that the edges of your circle are about one pixel width from the edge of you document, so you know that it won't be cut off in your circle cutter later. You can also do two or more border colors, just create another layer and repeat the process with another color, making the circle smaller than the first.
6. I save this image as PSP image, and as a JPEG. So, if I need to make adjustments later, it's easy. Now, create new a 4 X 6 inch document, and copy and paste your 1 inch document to the 4 X 6 doc. Duplicate the layer 14 times to end up with 15 images on your page----3 across and 5 down. Save it as a JPEG (and PSP if you want to be able to alter it later) and that's it!
Good luck!! If any of that is unclear, feel free to pm me!