Probability and Statistics Cookbook (2011) [pdf]
Actually quite good.I've TA'd this class but it's surprising how many of these little facts can be helpful if you recall them at the right time. I was just reminded of:  Var[Y] = E[Var[Y|X]] + Var[E[Y|X]]

and it unstuck me from a little puzzle.More recent version at: http://statistics.zone