If you want to measure resistance, set the function switch to the resistance range you want to use. For example, if you expect the resistance to be 1kΩ, set the switch to 2kΩ. If you have no idea what to expect, set the function switch to the highest resistance range available and work down.
Having done that, we can connect the test leads. Connect the black test lead to the COM jack and the red lead to the V/Ω jack. Connect the other ends of the test leads across the resistance under measurement.
Please note that in-cicuit measurement may lead to wrong results, since there may be other components parallel-connected to the resistance. It is also a good idea to make sure that the voltage across the resistance is 0V before starting resistance measurement. Also make sure that the equipment-under-test has been turned off!
Interesting links: Circuit Fantasia's electronics course