When you are finished working on your project, you'll want to bind off, creating a finished edge that will not unravel.
Binding off begins on the row where you are inserting the hook into the post to bring up loops. Instead of doing that, however, after you pull up a loop, you will then yarn over, and pull through two loops, leaving only one look on your hook. Continue to the end, pull the tail of the yarn through the last loop, pull to a knot, and then weave the ends into the side.
And that's it! Congratulations! You have learned one stitch pattern for Tunisian crochet!