What would cause the RPMs to actually go up to about two and a half when I step on the clutch? Normally it drops to just under 1.

extra vacum on your transmission. Check the vacum lines

Bad sensor in the fuel injection system

Are the RPM's normal when the car is stopped? Often times when you have a high RPM while the transmission is not engaged, it's do to a sensor on the engine. Temperature sensors will cause this most often. you could also have a bad or defective throttle control sensor if you AC is running. this sensor increases the RPM's of the motor to compensate for the power loss while the AC is running. some places to start.