<p>Personally I found that the youtube channel Crash Course was a great way to review material when I took APUSH and APWH. While some people can’t stand listening to John Green for an extended amount of time, I think the videos are entertaining. His brother has a chemistry/biology series, too, but I don’t know how helpful they are.
For any AP test I would recommend taking at least 1 practice test (and then study the questions you got wrong) and practicing with actual released FRQs.</p>