The "Fan resistor" (I hate that, it's a regulator, not resistor) is most often the culprit of any blower motor problems. If the fuse is good, then I'd order a 'resistor', very easy to change.

As to using your meter, if you take things apart so as to get to the 'resistor', you can measure to make sure it is getting the two things it needs:
1) 12 volt power
2) The enable signal from the controller, this is a 1.4 to 8 or 9 volt signal, the higher the voltage, the faster the blower will turn.

The other thing you can measure is the output to the motor - if you turn the fan **** to full speed, the output of the module should be very close to the input voltage (around 12 to 14 volts).