This is an area that is always in debate. Through my personal results, I like to set them up like this: (Carbs/protein/fat), As close to zero as possible/ 20-25%/75-80% of the days total calories.

SIMPLE OR COMPLEX CARBS?

I am assuming that you are doing a Cyclic Ketogenic Diet, where you will perform a depletion workout before the carb-up begins, right? If so, eat simple/high glycemic carbs at the beginning. The first couple of meals should be fluids (Ultra Fuel, dextrose, or grape juice). Protein should be whey mixed with water. Proetein is not a must at the beginning, so don't sweat it too much if you miss it in a meal. GET TO KNOW THE GLYCEMIC INDEX!!!!!!!!!!!!!!! A good site is:
http://www.mendosa.com/gilists.htm

As the carb-up process procedes, you can add in more "complex" carbs. Finally, try making your last 3-4 meals the same as your first couple of ones. High GI liquid carbs!!! This will help you re-establish ketosis faster. You can decide whether or not to eat every 2 hours or not, just make sure you get these meals right that I mentioned.

One last note here, if you find that you are gaining back the fat over the weekend that you so hardly worked off during the week, SHORTEN THE CARB-UP!!! Try a 24-30 hour carb-up instead.