Bettas are naturally meat eatters, But they will eat dry foods that are made for bettas/fish. The common brand that i strongly recomend is hikari betta bio-gold. Betta foods like this provide your fish a good balance of diet and nutrition. Many of them will also enhance the coloration of your fish. Meaty foods are also good for your bettas. Frozen bloodworms that are thawed in a cup of water and fed to the betta one at a time is a great food. They only should eat no more than five of these larve. Use caution when feeding freezed dried bloodworms. They are fine once and a while, but never as an everyday food. Freezed dried foods in general can cause bowel problems in fish when feed in excess. Dont forget that the food will expand in the bettas stomach so use very little and not everyday. Human food like peas are sometimes excepted, but I personally strong recomend not using these. Again they will produce a high risk for bowel problems. They dont really have any benefits so i would avoid them at all cost. Overall bettas arent really hard to feed, but the important thing to remember is not to feed your bettas to much and the wrong stuff.
If your having problems feeding
When you first get your new betta they may be hard to get them eatting at first. This is normal and nothing to worry about. Within a few days the betta will eat what you give it. For really stubborn bettas, I have found that allowing the fish to see itself in a mirror for a few minutes and getting them all active will make them eat faster. They need to rebalance themselves of use of energy causing them to eat.
New: Betta food reveiws,
Hiakari betta bio-gold is my favorite betta food. It is a simple pellet food that is usually accepted by bettas right away. It provides them with the balance diet that they need to fully develop.
Betta flakes, like betta min, i have had heard mixed results about. Betta flakes tend not to be accepted by alot of bettas so i wouldnt recommend it.
Betta bites, is another favorite food. I dont use it any more but it is a good small sized pellet that most bettas will eat. It is alittle more animal based then plant based, but that is fine.