Thanks, everyone. I have been spending time on the bettafish.com forums, so I am getting Betta info there. There are mixed opinions about filters. My tank came as a kit so it does have a small filter, so I can see how well that works. Right now I don't need a heater because my apartment is ways hot and I rarely turn on the A/C. But I'm planning on getting one for the winter.
It came with a light hood and a 15 watt bulb, too.
Anyway, thanks for the tips and the links for more plant info.
You're probably not going to grow anything with the incandescent bulb that came with your kit. As I stated in my original post, a 10 watt compact flourescent screw in bulb will. There are higher wattage cfl bulbs available too, but I don't have any experience with those.