I would suggest getting one of the test-prep books from a bookstore, and going through a few of each of the different kinds of problems. That way you’ll be familiar with the type of questions that are asked.

Brush up on your math basics – fractions, decimals, basic algebra – make sure you remember the procedures for the different types of problems.

Spend some time looking over the basic grammar rules, and some of the vocabulary.

Remember your basic essay structure – introduction paragraph (introduce your main ideas), body paragraphs (one main idea per paragraph), and conclusion paragraph (restate your main ideas).

Make sure you get a good eight hours of sleep the night before the test, and eat good breakfast that morning. Take a small (non-sugar) snack with you for the break.

Good Luck!