My A/C stopped working. where do I start looking?

2001 oldsmobile silhouette minivan.
I was driving with the a/c on. I turned off the van. When I turned On van again the a/c was not working anymore.
I checked the fuse control box under the dashboard. the fuses were okay.
I did the same under the hood. where I notice a relay for a/c control. i wiggled it but wasn't able to take it out.
Dashboard controls: a/c litted button goes on when depressed but a/c doesn't work. the fan blows uncooled air.

jaime
October 2005