alright read this betta care thread... http://www.fishforum.com/viewtopic.php?t=15392
yes a betta does need at least a 2.5 gallon tank.
and a heater is NEEDED! they do need 78 degree water constantly (its not a heat lamp, its a fully submersable heater that comes in diffent wattages (5 watts per gallon)) bettas dont need an air pump. they breath by gulping air from the surface. so make sure you tank lid has some air holes in it.
to feed it you should use either pellets or flakes, or both. you can feed it perhaps 3 pellets twice a day. and maybe a small pinch of flakes twice daily as well. somtimes your betta will not eat the first type of pellets/flakes you buy you may have to try a few diffent brands until you find one he likes. in my experience this is the worst part of betta fish keeping (picky little buggers
) it is also always good to give your betta variety- try picking up some frozen bloodworms or brine shrimp for a once a week treat.
depending on your tank size you would water change about 25 percent of the water every couple of days. and replace it with DECHLORINATED WATER. make sure you use water conditoner in the first place.I would recomend a sponge filter too to get rid of those suspended particles. oh and a handy turkey baster too so you can clean poo wasted food from the gravel.
well i think thats all. Welcome to the forum and good luck with your new aquairium friend :D