Males are very agressive towards one another and must be housed separately. I would recommend at least a 2 Gallon Tank, but a 5 Gallon or larger tank would be even better. While they can survive without filtration, I would recommend getting a filter. Lower flow is usually considered better for bettas, since it makes it easier for them to swim. Definately get a heater, as they will do better with a consistant temp and are a tropical fish. Some Bettas will tolerate tankmates, while others will not. It depends on the individual fish. The love swimming through plants, so a heavily planted tank (real or fake) is appreciated. If you go with fake, make sure not to go with something that their fins will catch and tear on. This usually means that silk plants are preferred over plastic.
Bettas are carnavores and will need a protein rich diet. Their are several fish food out there specifically aimed at bettas which will provide a good starting place. You will want to make sure to provide some variety with more than one food for better health. Perhaps some flake and the occastional brineshrimp treat. They love live food and will thank you if you provide it to them, however they will quite well on prepared foods as well.
The hype is do to their beautiful finage and spunky personalities. This is one fish that will definately interact with you.
