The first step in creating a signature is to give it a name. You start by clicking New and then typing the name in the New Signature box.
You can give your signature your name, call it "My work signature," or choose anything else. If you intend to create more than one signature, you may want to use more descriptive names for them, so that you can keep track of which signature to use. It's easy to know what's in signatures named "Business (simple)," "Business (all contact info)," "Personal (Soccer Team)," and so on. You'll learn more about creating multiple signatures in the last lesson of the course.