Bodybuilders are usually diet nazi's. We don't like to give information to people who don't use it.
Diet:
For your instance - I would seek a diet with 45% of the calories coming from Carbohydrates, 35% coming from protein, and 20% coming from fat. Remember 4 calories per gram carbs and protein, 9 cals per gram from fat. Set your caloric intake at your body weight x 12 (if you are working out) or x 10 (if you are lazy and are not working out) Divide your calories into 6 or so meals. Space an equal serving of protein throughout these meals.
Example foods -
Carbohydrates - Brown Rice, Oatmeal, Wheat Bread, Whole Grain pasta, Veggies, Fruit
Fat - Nuts, Peanut Butter, Healthy Oils, Egg yolks, smart balance or butter spreads
Protein - Fish, Chicken, Lean Beef (reccomend 90/10 or better), Eggs, Protein shakes
This is definitely not an exhausting list so look more up when creating your diet.
Training: Get in the GYM! Build a daily habit to get in there! Find someone who knows how to lift and group up with them. I would suggest hitting 2 muscle groups hard every day and following that with 30 minutes cardio. If you are one of those people, who are like 'I don't want to build a lot of muscle, i just want to be a thin weenie the rest of my life.' then go to weight watchers. You are in the wrong place.
Supplementation: After a couple months of consecutive gyming, consider the use of creatine monohydrate.
This is the tip of the iceberg, use search and start acting!
Get bit by the iron bug, I love it!