haha Aimee you beat me to it!! I was going to write a care guide, but since we got yours i'll just add to it. Ahemm...
Temperatures:Bettas do best in a temperature of 75-82 F. Sudden drops or spikes in the temperature can be very stressful to your betta so try to keep it stable. Like Aimee said, heaters are great to have.
Water Changes:It's highly recommended that you do weekly water changes of 1/3 for 2gal tanks or bigger. 100% weekly water changes for anything less, but if your bowl is a quart/liter or less then 100% daily water changes are a must. Refill with previously treated and aged water of the same temperature. Clean water is the number one preventive to sick fish!!
Foods:Bettas can be very picky eaters, so if nothing works try live or frozen brine shrimp or blackworms. They may also eat pellets but try to stick with Hikari's betta pellets since they are the best kind. Also pellets expand which can cause problems if overfed, so keep the amount to 3-4 daily. Another type of food they may eat is freeze dried bloodworms and brine shrimp. Feed a small amount of these as they also can cause serious problems if overfed, and if you come across any hard pieces throw them away. Finally you have flakes. I haven't heard much for sucess stories with flakes, so your probably better off with something else.
And finally here's a few things to look out for...1) Sharp edges on any decor.
2) Having your bowl/tank without a cover (bettas do jump out of their homes)3) Having your Bowl/Small Plastic Tank close to an edge when you have pets/kids
4) Hungry Cats