welcome to the forum and to fishkeeping. i recently got a betta myself and love it. i inherited a 3 gallon eclipse tank from a friend, kicked out its residents and moved him in there. he is pretty darn happy in there. and despite what many people say, he love the tiny current from the filter. those leisure time is still sleeping on rocks or leaves.
i don't have a heater for mine and you probably won't need one, but for a ten gallon tank a 50 watt heater would do you fine.
i have two live plants in mine (anubias and somehting else, both inherited) but i guess it all depends on what kind of tank you want to keep, planted, or simple
and that leads me to gravel... if you go planted you could use something liek eco-complete or flourite, but you can always use regulare gravel fomr the lfs that you rinse and put it. it is all to personal taste.
bettas are real hardy fish and can tolerate real crappy water. which is why many people find them easy to take care of. their stomachs are about the size fo their eye so you can feed them 2-3 pellets of food every other day(lfs store dude recommened.) mine got accustomed to feeding after the first time; where i had to entice himt o the top and see me put the pellet in. but after the first time he pretty much can tell when it is feeding time. its a pretty rewarding experience having that interaction with him.
everyone might give me flack about it, but i think a simple filter(ie whisper HOB) would make you very happy. not only will it move the water a bit, but it will save you on water changes. i change mine every other week(1 g for 3 g tank.) which makes care for him easy. you can run a tank with water for a few days or a week before you put him in, and he will survive in there nicely.
i use a small, very small amount of aquarium salt in my tank. this is a hated practice by many, and i was reluctant at first, but my betta seemed to like it when i did. plus it will thwart most chances of disease. I read about it on a betta keeping site sometime late at night, but the woman who said it swears by it an breeds them.
lastly, since he will probably be alone in the tank, you can put a mirror up to it for about five minutes a day. if you do it on the side of the tank, you will have a fun show!
enjoy your betta. don't forget to give him a name!
