In the sewing/quilting notions section at most fabric stores or quilt stores you can purchase packages of fabric made just for this, and you don't have to reverse your photos...one brand name, which I use, is Precious Treasures (I think!)...the paper is prepared to accept printer inks, ironed onto paper and cut to size for use in printers. this brand is designed for ink jet printers only....don't use on laser jet. (some brands are designed for laser jet, so purchase what you need). Instructions in the package are clear as to how to do it so read and follow the instructions in the package you purchase. I always use the "sew in" type, so after the photos are printed and dry, I cut them to size and stitch them into the block just like I sew in any other fabric. Some brands are designed as transfers, as Barbara discussed, some are iron on, etc, you need to decide what works for you and find the product.
Good luck.