If your trigonometry is weak or rusty, I recommend that you begin reviewing it as early as possible.
To aid in this review, we have put together a few recommended resources and suggestions of what to study.
The best way to get started is to try to do as many practice problems as you can!
Keep a list of the definitions/concepts/computations which you do not understand or struggle with. Bring this list to office hours or the Math Resource Center for one-on-one help!
Step 2: Whenever you want to review a topic, or when you get completely stuck, you should watch the following review videos.
You can also find assorted video explanations at the Kahn Academy website. Khan Academy will give you a review problem after every couple of videos, but don't stop there! Once you better understand the material, do as many practice problems as you can!
Step 3: Once you have the basic ideas, you should read Dr. Oussa's excellent A Quick Review of Trigonometry. If you want even more details, you can read the trigonometry section of any book on Precalculus. For example, you can read Chapter 8 of Stitz and Zeager's Precalculus Textbook (free to download).
Step 4: To retain your knowledge, you will need to use it frequently. To help refresh your memory if you get stuck, you should refer to this short (2 page) summary of the most basic, and most important, trigonometric facts we know.
During your entire review, feel free to come to office hours and ask me questions about course or review material. I would be happy to answer any questions, or to point you to things I think are worth focusing on.