-(optional) If using dried beans, place the beans in a large bowl and add enough water to cover by 2 inches. Place the bowl in a cool place and let the beans soak for 6 to 12 hours. Drain and rinse the beans. Put the beans into a large pot and add enough fresh water to cover the beans by 1 inch. Bring to a simmer over medium high heat, reduce the heat, cover, and simmer until the beans are barely tender. 1-1/2 to 2 hours (depending on the age of the beans). Thoroughly drain the beans and let them cool. Put the lime juice, olive oil, garlic, salt, and cayenne in a small jar. Cover with the lid and shake until the ingredients are well mixed. In a salad bowl, combine the cooked or canned beans, corn, avocado, bell pepper, tomatoes, green onions, chile pepper, and cilantro. Shake the Lime Dressing and pour it over the salad. Stir until well coated. (The salad can be prepared a few hours ahead, but don't add the avocado until serving time. Refrigerate, and adjust the seasonings before serving.) Makes 4 to 5 main-course servings or 8 to 10 side-dish servings.