Content:

Unit Circle
Trig Formulas
Blank Tables
Detailed Material
Exercises
Answers
Exercises2
Answers2
Exercises3
Answers3

Trigonometry is the area where you will have the greatest need of preparation.
I suggest that you start by learning the Unit Circle and understand what is meant by radians.
To practice the most important values, you can download some blank tables here.
Go on by learning the Trig Formulas, and then do the exercises.
Finally, you can look at the detailed material which will make you perfect in Trigonometry.