College Test Preparation
Doing well on the ACT or SAT can have a huge effect on your college career. For starters, it will determine where you can go to college. These days, even public universities have cut-off points for college test scores.
Some ways to improve your results:
Take a test preparation class. Some can be a little pricey, but it you're not comfortable in a testing situation, they can help you be more confident.
Definitely review the test guide. For the SAT, that's the College Board's Official SAT Study Guide. You can get it on Amazon.
For the ACT, there's The Real ACT Prep Guide and an online practice test. Order the guide on Amazon.