Getting Bata for small tank...............

Question
Hello! I'm VERY new to tanks and fish. My tank is a 1 gallon fresh water tank with an air stone, its triangle in shape, was given as a gift. I have read on several sights and books as well that a Beta needs a certain temp. to stay happy and healthy. Do I need some sort of heater? Could I add another fish to this tank at a later date and if so what type? Could I only use FEMALE Bata's in this tank, if so how many? I would like to use this tiny tank as a starter tank then move up in the world to a 5 gallon after the summer. I live in TN near the Alabama boarder so its HOT during the summer yet bitter cold in the winter. When I get the 5 gallon tank where is the best place to put this tank so the tank wont get too cold or hot? Ms. Barbara I know I'm asking allot of questions of you so please over look my lack of knowing about fish or tanks. Thanks for your help in advance. This sight is GREAT!!! Everyone here has given me LOTS of info and helped me in more ways then I can count!
Thanks again, Leesa :)

Answer
LOL sorry leesa, never checked my comment box til now.

As far as petco or petsmart, they seem to be alright. Bettas from local pet stores tend to be older, which cause them to die quickly. When I was younger, I relied very much on petco for bettas. If you are really looking for good bettas, you can purchase them from internet from official breeders. If I have some bettas for sale now, I'd say get one from me ;] but my last baby was sold couple of weeks ago and I only got my breeding pairs left :[. I believe petco has one day of the week, where they get all bettas at once, so that day is the best day to get one. That's when they just got shipped and are healthiest. Though, if you purchase them that day, they will be stressed from being shipped, but it is much better to get them then to leave it at the store, where they have to suffer in such little cup all night. Avoid ones with very long, flowing fins for males becuase that is a sign that the betta is old.

Good luck with your betta! Whichever betta you get will be super lucky to have you as his/her owner! :] xoxo