According to a KipTip in January Kiplinger's Personal Finance magazine you should divide it as follows:
Clothing: 5% (Ouch)
This makes sense to me, though I do mine a bit differently. You have to personalize this but there is wisdom in watching your percentages. You don't want 50% of your income going to housing and 20% to clothing (well, you may want that). Watch where your money is going and make sure that if you're percentages are out of whack, you reevaluate how to get back in track.
Hope this helps. Happy budgeting friends.