Does anyone have good reference points when to start dating during/after a divorce?

For perspective. My wife served me divorce papers last week, I moved out about a month ago, my wife has told me she wanted a divorce for about three months, and she has already started dating our au pair's college friend. We also have a 3, 4, and 5 year old, who are my world.

How do I know when I should start dating? Is there a 'a-ha' moment where you are ready? Any advice?