30mins of exercise at least 3 times a week, 3 meals a day along with 2 healthy snacks, including protein in all meals, drinking heaps of water will give you a very good start. Once you gain more energy (which you will) you can increase from there. My biggest tip is to find exercise that you actually enjoy. If you hate walking and bike riding, don't do it. I hate walking and bike riding and never do it! Things I love are crossfit and martial arts classes, skipping, cross trainer, horse riding, workout dvd's and that way I actually look forward to and enjoy exercise.
With regards to food, calorie king is a great site to use, it really educates you to know what foods contain what calories and to get a balance of carbs, fats and protein. Be wary of foods that say they're 99% fat free and all that because most of them contain heaps of sugar so aren't that much lower in calories in the end, also, foods with fat are not something to be scared of, we need fat in our diets, it is just a matter of choosing the good fats, not the saturated ones. You also want to avoid the artificial sugars as they're no good for your body. It is all a learning curve, but calorie king and finding exercise you enjoy are a good place to start.
Have fun!