i'm going in just with barron's. and.... the world is flat. though i didn't even self study yet, so i'm not sure how "the world is flat" is going to help =P
but glad i have at least 2 texts.
as for the text book...it was out of stock and the individual sellers can't sell them to me so... )=
If you're using anything more than the Barrons study guide book it's complete overkill in my opinion, i walked into the test never reading a textbook and only using my Barrons stduy guide knowledge and my common sense and walked out knowing i got a 5. Don't try to worry yourself too much, it's the easiest AP exam i've ever taken by far.
There are free responses for every AP Exam. I am not sure I would call the responses for this exam "essays," though... I don't think you have to go with some thesis/body paragraphs/conclusion thing. You just gotta write down the information they want.
