The book says,
Learn the art and craft of creating a beautiful piece of a stained glass by signing up for a hands-on class. A class can provide you with an in-depth exploration of the types of glass productions, materials needed for a project, the design work of a window or panel, and other ingredients necessary to produce a stained glass project.
While your instructor will be able to teach you the basics, it is often through hands-on work that you gain a comprehensive understanding of the art form. You'll meet new people in your stained glass class and, who knows, one or more of them might become friends with whom you can spend happy hours creating works of art. In time, you might even choose to organize a show, establish an art collective, or sell your creations through word of mouth.
If this is a hobby that interests you, check on Pinterest. There are tons of ideas on that site. The pic above is the Tree of Life that I found on Pinterest. Also, don't forget to check out Etsy. That is also a site for crafts and hobbies.
Links of Interest:
Beginner Stained Glass Kits
Stained Glass for Dummies
Free Stained Glass Patterns for Hobbyist