Here's a brief tutorial on how to use that meter:

Plug the black test lead into the "-COM" port, and the red test lead into the "+V-OHMS-A" port next to it. Then set the dial to the 15 setting in the "DC V" section of the dial (for batt packs less than 15V). Then you can read the voltage off of the "0-15" range of the DC section of the meter. If you are unsure of the voltage you plan to measure, it's best to start out at a higher setting and work down. So if you don't know if a voltage is less than 15V, then you should start with the 60 setting in the "DC V" section of the dial, and read the voltage off of the "0-60" range of the DC section of the meter. If that shows the voltage is under 15V, then you can drop down to the 15 setting and read the voltage off of the "0-15" portion of the DC section of the meter. To measure the battery voltages under load, simply connect the appropriate resistor across the test leads, in parallel with the battery. Rodney suggested some load resistors for different battery packs in a previous post.

There are 10 small tick marks between numbers on the DC portion of the meter, so that means each tick mark is 1/2 a Volt in the 15V range setting, 2V each in the 60V range setting, etc.

Hope that helps!