The PSAT is really supposed to be a "practice," so don't get too worked up over it. If want to do well on it anyway, I would buy one of the books already mentioned or the Princeton Review one. Be sure to get plenty of sleep during the week prior to the test. Wake up earlier than usual and do some homework or get exercise (or both

) so you are used to working early. Eat a good, healthy breakfast, but don't eat too much or you'll get drowsy. Bring a snack with a drink without caffine to munch and sip on between the test sections. You could drink something with caffine, but remember that it may wear off in the middle of one of the sections and cause you to feel like you have lost energy. Bring about 5 pencils (better safe than sorry

) and a set of back up batteries for your calculator (
make sure they work). Bring a graphing calculator if possible, and make sure you know how to use it
well. Be sure the one you bring does
not have a keyboard!
If you want to do well on it for so you can qualify for a National Merit Scholarship, don't bother. Only 11th graders are eligible for the contest.
I took it last year in 10th grade too. It's always good to get as much practice as possible before starting the real thing.
EDIT: aYe kANt sPieL foUr KRaP!