It's simpler than you think...and more complicated.

This time of year, all of us in Texas education are busy trying to inspire our students. We create study sheets, offer tutorials, search interesting videos.
The Missing Ingredient that I see is the art of study. 
I'd love to tell you that there is a shortcut...that some reading trick or way of highlighting or hunting for key words will help you master this.
The only way to pass the TAKS test, and in the future, the End of Course exams, is to behave and think like a student. That means taking notes in class, reading assignments, completing work, and (gasp!) studying at home. Pull out those notes. Underline the most important terms. Look up terms you don't know. Review. Go to class the next day seeking to find answers to anything you didn't understand.
Take it from me, teachers are not trying to trick you into failing their class. For the student who comes with honest questions, a teacher will give time and effort reteaching concepts that weren't absorbed the first time.
There is no need to panic over the TAKS test. If you learned a little every week, worked on your quizzes, completed homework, took notes, asked questions in class, you have nothing to worry about. Piece of cake. You'll probably also pass the SAT.
But if you slept through class, failed your essays, got 70's by the grace of God on geometry tests and 55 on IPC benchmarks, your readiness for TAKS is dubious indeed. While your teachers looked in vain for you in tutorials, gave you second and third chances on make-up work, you allowed the learning window to slam shut. Don't make the same mistake next year.
There are some subject that you can absorb strictly through sitting in class, perhaps. It depends how high your IQ is and how much you absorb strictly through listening. Most people need to see, hear, and then demonstrate concepts to hook into them. That means reading, listening, writing, and then applying a concept by working out problems or lab experiments or open-ended-response questions. For learning to take place, your brain has to wrestle with a topic and master it, pin it to the mat and make it cry "uncle!"
For you to hit the books now, you would need to have 8 months worth of good notes and some solid skills in order to be ready. Are you? I certainly hope so.