When dealing with the unit circle, sometimes it's easier to remember angles and convert them to radians.

The angles along the unit circle in degrees are

0, 30, 45, 60, 90, 120, 135, 150, 180, 210, 225, 240, 270, 300, 315, 330

To convert angles from degrees to radians, multiply by Pi/180.  Therefore the above angles in radians are

0, Pi/6, Pi/4, Pi/3, Pi/2, 2Pi/3 3Pi/4, 5Pi/6, Pi, 7Pi/6, 5Pi/4, 4Pi/3, 3Pi/2, 5Pi/3, 7Pi/4, 11Pi/6

The values for sin and cos along the unit circle will be +/- 1/2,  +/- sqrt(2)/2, +/- sqrt(3)/2.  The + or - depends on what quadrant the angle falls.