UK and Canadian and American Vocab Equivalents?

Reading through these I have found a lot of terms I'm not familiar with, like Kip (as in "when he [a baby] is having a Kip) is that a Nap. And a Health Visitor, is that a Doctor, Nurse, or what is the US equivalent? Also, this question mentions placement in a pre-school, is pre-school free in the UK? Equivelents of any other terms that are common in other Countries would be most insightful! Thanks