That's a handy and simple meter to use.
Just match up what you're testing with the selector BEFORE you touch the probes to the circuit.
You know what type voltage you're testing, AC or DC.
You know the maximum to expect, so set the selector to the next highest setting.
Example, you want to test a receptical in your house. You know it's 120 volts, AC voltage. Set the selector on 250 volts on the AC scale. The meter will read about the middle of the scale if the circuit is hot.
If you want to check continuity, set the selector on the OHM setting. Connecting the leads together will cause the needle to swing all the way to the right. Just be careful not to forget to change the setting off OHMs before connecting it to a live circuit. It will probably smoke the meter. There is a battery inside the meter. If connecting the leads together doesn't move the needle, the battery is probably dead.
This type meter is not going to be real accurate. It will basically tell you if a circuit is live or dead, or tell you if you have continuity through a circuit.
The advantage over a digital meter is it will respond much quicker than a digital if you are trying to catch an intermittent signal. The disadvantage is it is not as accurate.
Just be careful using the meter, don't bet your life on it! The leads are tiny and prone to break internally. They could show a circuit to be dead when it really is hot!