Theoretically you should allow a manuscript to cool for 2 weeks before going back into it. The idea being that you will see it fresh and anew.
But really, if you have the desire to launch right into editing, you should,
See, that creative energy you feel when you create a book...well, it has a shelf-life. Just because you feel charged & motivated NOW, doesn't guarantee you will feel the same way in 2 weeks.
That energy is fleeting, and when it seizes you, go with it.

I have done both: waited the 2 weeks, and just torn into the manuscript...and honestly I saw no difference in the final draft. But the times that I stayed away, it seemed harder to get back into the groove.