How to prepare for classes?

I want to do really well in my classes next year, but unfortunately I didn't have the best teachers so I didn't really learn much, and some subjects I'm just not good at. How can I prepare for:
Precalculus: I had a horrible math teacher for the past 2 yrs
AP Chemistry: I'm not horrible at the basics of chem, but math is not my strong suit
American Sign Language: I've never learned. I know about 1 letter.

I have done my hw for chem, and bought precalculus demystified to help me. What are some basics besides slope and functions that I should focus on? And this is the first year my school is offering ASL, so what should I know going in?
Thanks

Interested Reader2014-08-07T12:28:50Z

In college, I learned to read the textbook for each course before I went to the first class. There were no surprises that way. The next thing I learned (taking counseling courses) was to restate the beliefs and attitudes of the teacher on all tests and exams. The only times I violated the second rule was when his beliefs or attitudes were not consistent with what I believed God expects of me. Interestingly, I still made excellent grades when I disagreed with a professor when and if I was able to present a logical defense of my beliefs and attitudes. I never bothered to attack the beliefs of a teacher; only presented my best defense of my own. I graduated twice with a 3.5 GPA.

Knight2014-08-07T12:04:21Z

I find the most influencing factor for a person is his or her record. If there's no reward for right actions, there would be no guidance to motivate to achieve. I find myself procrastinate. So I made a progress report for myself. By working according to the progress report, I balance rest and work and motivate myself from step to step. You should make a study schedule for your classes too.

breasia2014-08-07T12:02:36Z

First off, I would take full responsibility for success or lack thereof in my classes. If you are dedicating yourself to the classes you must have and fully commit to your success in these classes, no excuses allowed, then you will be successful.
1. Pay close attention.
2. Take notes.
3. After class review your notes.
4. If you have any questions that arise, make an appointment with the teacher and have him/her clarify.
5. Study, study, study.