AP test prep

How horrible on a scale from 1-10 is it that I have read and started using AP test preparation literature in our history, English, Math and Sciences curricula? I’m using them, in the sense that I am making sure whatever we are studying includes details the tests might inquire about, and in the sense that I make sure our studies include topics the tests might include. 

Why? 

1/Because I know our kids will have to take these tests and do well, and 

2/because I didn't grow up in the US educational system, and frankly have very little knowledge about what they teach over there, or expect the children to know. For example, comparing my world history education to that of my husband’s (who did go to school in the US), I know the boys are at an advantage, but I’m not sure about the other subjects. 

I know what my husband & I want our boys to know (and we do have pretty high standards, as far as I understand), but do these requirements measure/line up with those of the AP exam? Will all the knowledge and skills we are providing them with be sufficient or even of the right kind?

There’s only one way to make sure, right?