my way is to eat 2500 calories with a 20/50/30 split of fat/carbs/protein,
get a good dose of oily fish or chicken at least every other day and eat starchy carbs and leave out the sugary simple carbs, as for weights, i think other people have pretty much covered it, just remmber to do back weights too, otherwise youll end up hunched over.

@the person who said muscle turns into fat, your wrong, muscle is an expensive body commodity, it burns 15 calories per unit compared to 4 calories per unit of fat, thats why big muscly people can eat more, when you dont eat enough or the body decides you dont need the muscle it turns on itself and breaks itself down, if you stop doing exercise but still consistantly eat lots, it wont turn into fat, youll just gain fat and lose muscle.