All the feedback convinced me to go ahead and get some fabric for the backing. It'll be more pretty that way and will make more sense, since I have been wanting to include some squares with back pockets. The raggy side will the denim side. With the fabric on the back coming through on the front, it should be really pretty.
Dunster - I already have two pair of spring-loaded scissors; one large and one "micro" set. My squares are 8x8, but I am only doing the single layer of backing - the denim and single flannel squares so be plenty warm for mom. =)