SAT subject Tests: Bio, Chem, U.S. History

<p>This fall I plan on taking the biology (M) subject test, Chemistry subject test, and also the U.S. History Subject test. I was wondering which book(s) would be appropriate for these subject tests to achieve an 800. Also would it be a smart idea to take 3 subject tests in 1 test day? I have not taken AP classes for the above classes, but i have got a B+ in bio and chem, and an A- in U.S. History.</p>

<p>Plus, any study methods or strategies? i am willing to put 4 hours per day on weekdays and 2 hours per day on weekends</p>