Trying to lose weight - help?

Hi, basically I'm a dancer and I am trying to get fit and lose a bit of weight, and I mainly need exercises for my stomach. What kind of exercises should I do for my stomach to get toned - how many, and when (daily, weekly etc)? Also, what kind of things should I stay away from which are fatty and full of calories and which foods are healthy and good to eat? A plan of what to eat daily for breakfast, lunch, dinner and snacks would be great, thank you!