Summarize:

For the most accurate measurement, test the resistance of a component individually. Remove the component from the circuit or test it before you install it. Testing the component while still in the circuit can cause inaccurate readings from other components.  For example, you might test the switch or motor. If you are testing a circuit or even just removing a component, be sure that all power to the circuit is turned off before proceeding. On most multimeters, one test lead will be black and the other will be red. A multimeter often has multiple testing sockets, according to whether it is being used to test for resistance, voltage, or amperage (current). Usually the right sockets to test for resistance are labeled "COM" (for common) and one labeled with the Greek letter omega, which is the symbol for "ohm." Plug the black lead into the socket labeled "COM" and the red lead into the socket labeled "ohm". The resistance of a component can range from ohms (1 ohm) to megaohms (1,000,000 ohms). In order to get an accurate reading of resistance you must set the multimeter to the proper range for your component. If you have a general idea of the range of resistance just set it to that range. If you’re unsure, you can determine the range through trial and error.  If you don’t know the range, start with the middle range setting, usually 20 kilo-ohms (kΩ). Touch one lead to the end of your component and the other lead to the opposite end. The needle will swing across the screen and stop in a specific spot, indicating the resistance of your component. If the needle swings all the way to the top of the range (the left side), you will need to increase the range setting, zero out the multimeter, and try again. If the needle swings all the way to the bottom of the range (the right side), you will need to decrease the range setting, zero out the multimeter, and try again. Analog multimeters must be reset or zeroed out every time the range setting is altered and before testing the component. Touch the ends of both leads together to short the circuit. Ensure the needle is set all the way to zero using the Ohms Adjustment or Zero Control after the leads have been touched to each other. Just as you did when you were setting the range, touch one lead to one end of the component and the other lead to the opposite end. The resistance range on a multimeter goes from right to left. The right side is zero and the left side goes up to around 2k (2,000). There are multiple scales on an analog multimeter so be sure to look at the scaled labeled with an Ω that goes from right to left. As the scale goes up, the higher values are clustered closer together. Setting the correct range is crucial to being able to get an accurate reading for your component. Once you have touched the leads to the component, the needle will settle somewhere in between the top and bottom of the scale. Check to make sure you are looking at the ohm scale and record the value where the needle is pointing to. This is the resistance of your component. For example if you had set the range to 10 Ω and the needle stopped at 9, the resistance of your component is 9 ohms. When you are finished using the multimeter, you want to make sure it is properly stored. Setting the voltage to a high range before turning it off ensures that it won’t be damaged the next time it is used if someone doesn’t remember to set the range first. Turn off the multimeter and unplug the leads for storage.
Choose the item whose resistance you wish to measure. Plug the test leads into the correct test sockets. Turn on the multimeter and select the best testing range. Touch the multimeter leads to the ends of the component you are testing. Read the resistance. Set the voltage to a high range.