Oh, he is so vibrant! Bettas are easy to take care of, as long as you plan on giving them just as much attention as you would a dog or cat. Read about the nitrogen cycle on the Freshwater Beginners Page. That is a wealth of knowledge to help get you started. A variety in the diet is a big thing... my bettas get pellets, bloodworms, daphnia, peas and other fruits and veggies... NOT ALL AT ONCE. Only feed them small amts. b/c their belly is no bigger than their eyeball. Make sure their is NOTHING in his tank that would snag pantyhose b/c it will tear his fins. I can't think of anything else right now, but I am sure that others here can help. ;D
If you mean you want to rescue another Betta you do know that you can NOT put two Bettas in the same tank, not even a male and female. Bettas don't get along well with most fish other than some peaceful bottom feeders like Otos and Cories. They are best alone in a tank. It would be great if you could rescue another Betta but he or she will need a different tank.
It constantly amazes me how one little fish can come in so many amazing colors and styles. He's so flashy and bright! Very nice looking boy! Congrats on saving him from his little cup of doom...