Rick Riordan’s Percy Jackson series is a great place to start when wanting to learn about Greek mythology. These young adult books are not only highly entertaining, but they also provide an insightful look into some of the most important gods and goddesses of Greek mythology. Some readers may find the lighthearted tone a bit juvenile, but many enjoy the engaging storytelling and vibrant characters.
However, if you want to just get an overview of the names and symbols of the gods, it may be helpful to choose an illustrated book or one with a more encyclopedic form.