Do they have sewing machines? If not, are they planning on making what, for many people, is a major purchase (even at the low end)? Too often I find people who ask me to help them learn to make a quilt assume that I make them entirely by hand -- or at least that I am capable of doing such a thing. I was blessed to grow up in a home that had a sewing machine; not everyone had an extra $100 to spend on a machine -- not to mention all the fabric, basic supplies, notions, etc.
If they have or are planning to purchase a machine, I'd agree with those who suggested starting with how to properly set-up and thread their machines. Once they've learned that, I'd move onto precision cutting (& rotary blade safety). No amount of effort spent on a "perfect 1/4" seam" will amount to anything if the pieces aren't cut exactly to begin with. Once they've mastered that, working on patchwork seams would be the next logical step. Many quiltmakers are only interested in the piecing & that may be the case with your students. But if they also want to quilt their top, I'd go with a full SID quilting pattern to start with.