We just replaced the ceiling fan downstairs with a new one. I never can remember which direction the blades are supposed to go. However, I looked at the instruction book and decided to post it here, since I know this comes up from time to time. (Then I will archive it so we can find it when we need it!).
DOWNWARD AIR FLOW (used in warm weather)--blades go counter-clockwise.
UPWARD AIR FLOW (used in cold weather)--blades go clockwise.
There is usually a switch on the side of the fan housing to reverse the blades. Pull chains are usually used to stop and start the fan, or turn on the light.