Example for a 200-lb man:
Your goal should be to eat 350 grams of protein (1.5 - 1.75 grams per Ib of bodyweight) and to eat about 450 grams of carbohydrates per day (2.25 - 2.5 rams per Ib of bodyweight). Your caloric intake should be about 3700-3800 calories per day. This amount should be enough for good size gains without fat.
For solid protein, you should be eating five servings of 30 grams per day. For example: 5 chicken breasts (30g of protein each), or 5 cans of tuna (30g each), or mix them up (such as 3 chicken breasts and 2 cans of tuna, etc). (4 oz of turkey is about 30g of protein and 5 oz of lean red meat is about 30g of protein also).
I am going to suggest taking three protein shakes per day at about 60g each, so with the solid protein (150g per day) and liquid (180g daily) you should be getting enough protein. (This doesn't include the protein you are getting from oatmeal, etc.)
Carbs are the easy part. In general, for solid carbs you will only need to eat them about three times per day. Try oatmeal, fruit, potatoes, rice, or pasta. Take in about 75 grams per meal two times per day and 30 - 50 grams once in the evening. That is 1 cup of oats with one piece of fruit, 3 medium size potatoes, 1 medium size bowl of pasta or 1 large bowl of rice. For liquid carbs you should take in about 5 scoops of GlycoLoad after your workout (125g of carbs).
Don't count fat grams, because you get enough in your regular foods (about fifty grams per day which adds 450 calories).
I overloaded on the protein because that is something you should shoot for. You might not be able to eat that much in one day right away, but try to eat almost that much, because you will notice better gains. Also, your schedule might not allow you time for that pre-workout snack. You don't want to eat protein too close to your workout (45 minutes or less). Your body has no problem digesting carbs during a workout.
Listed below are some more foods for you to choose from to build your mass diet .