My fan won't start on my 93 mercury villager.?

Ok, I was taking my kids to the bus stop this morning and on the way home I notice a little smoke coming from under my hood. I looked under the hood and smelled antifreeze. I checked all fluids and everything looked fine. Upon further investigating I noticed that the fan (cooling ?) wasn't going. I did tap the motor to the fan and also turned the ac on and that did nothing. Can anyone tell me why it is smoking and the fan isn't going or what could be wrong? I have no leaks and the car did not run hot. I only went a few blocks though.