You do not realy need to let it sit at all. Just clear the runnings and drain. If you are not doing a mash out i would suggest getting your sparge water hot enough to get the grain bed up to 168ish, for me this 181. I had an increase of 20% extraction when i brought my sparge temps up.
primaries: BRown Ale
secondaries: Rye IPA
Bottled: IPA, Pigs ear brown clone, stovepipe porter, German Alt, Oktober fest ale, Smoked IPA, failed pale ale, 1st AG ESB, belgian wit, Ipa#2, , Lake wheat, fish Red ale, Smoked wheat,
KEGS: blonde Nugs , Sugar pale light, chin nook ale (gone in 1 week)