Here are the basics to using an ohm meter to test circuits and sensors on your vehicle:
Many sensors operate as variable resistors. Throttle position sensor, for example, gives one resistance value at closed throttle, a greater one at half open throttle, and an even greater one at wide open. A service manual will tell you the specifications for this resistance in ohms. Compare the values you measure with those in the manual. If they do not match, the sensor is likely bad.
Fuses are designed to have either no resistance at all (zero ohms), or, if they burn out, to open the circuit (infinite ohms). If there's any doubt as to whether they're fried, pull them out and measure the resistance across them.
Use the volt meter function to see if components such as your ignition coil are getting power. The battery and charging system should supply everything with about 13.5 DC volts. If no voltage is present in a circuit, something is wrong like a blown fuse. If there is a lower voltage, check for bad grounds or a possible faulty battery or alternator.
I know this is all in pretty vague terms as far as your problem goes. I don't have my service manual handy so I can't give you any specifics on resistance specs. Hopefully, though, you now have a better basic understanding of how to use a multimeter.
