This very much depends on your goals. If you are trying to lose body fat, then you should take minimum carbs and usually early in the day.
For maximum muscle gain and weight gain you should take as much as possible. There is no right or wrong amount. Take in as much carbohydrates as you can on a daily bases, train hard and if you see that you are getting more fat that you like, lower intake. Otherwise, keep taking carbs until you reach the size you desire.
Good sources of carbohydrates are pasta, potatoes, rice, bread.