Don't think there are any hard and fast rules, since every person and every situation is different. Personally i would not advise less than a year. I've never faced it, so i know it's easy to say. But i've got that long and longer having not dated, so it's doable.
You need to give yourself time to recover. There's usually more residual affects after a divorce than most people want to admit to. You don't want to bring you recent issues with you. And sometimes people who move too fast end up feeling smothered for not having taken time after divorce to have time to themselves.
But if you meet someone good, and haven't taken time to heal and mend from the effects, seen and unseen, then you will simply carry it with you into your next relationship and it will fall into ruin as well. Better to spend too much time healing, than not enough.