Did you get it tested?
If not heres some step by step instructions for your meter...
The charging test is easy, lets start with that.
Like WullFVR rightly said. Put the black lead in the COM, and the red lead in the V, to the right of the black lead. The picture you posted shows the multimeter set to 2amps DC, we'll get to amps / leak test next. Going back to the picture, the opposite end of the knob is in the DC Voltage section, which is what we'll need to check it's charging the battery, so flip the dial the opposite way around and then down one more to '20'
Make sure the battery is fully charged before doing this test, after charging it up, connect the multimeter (as set above) to the battery (with the engine off first of all) the end of the red lead to the Positive (+) terminal and the end of the black lead to the negative (-) terminal, a fully charged battery should show aroudn 12.8 on the meter, any lower and check the batterys charged.
Now, start the bike, warm the engine a bit and hold the RPM at 5000. (It's easier if you have someone to help) Put the meter back onto the battery like before, end of the black lead onto the Negative (-) terminal of the battery and the end of the Red lead onto the Positive terminal of the battery (+).
The multimeter should now show between 14.1 and 15.1v if the charging circuit is working properly, anything outside this range points to a knackered reg/rec, altenator wiring or at worst case both.
Leak Test.
Ignition off!
The picture shows the meter set to test for upto 2amps DC, thats fine so leave it at that, the black lead stays where it is in the meter, but put the red one in the hole to the left this time, (marked A). Disconnect the earth cable from the Negative (-) terminal of the battery.
Put the end of the red lead to the cable you've disconnected and the end of the black lead to the battery terminal.
Your meter should show 0.01 or less, if so you can bring the meter down a setting (200m) instead of 2, keep bringing it down a notch (move the dial clockwise) until you get a reading, you want a maximum leak of 1ma.
If you don't have current leaking to flatten the battery, it stands a chance that the battery is fooked, when this happens they short out inside causing discharge over-time... the most common cause of this besides the battery being old is being over-charged, so if it comes to replacing the battery, double check your charging circuit again!
Hope that helps!
http://www.akhara.com/nc30/nc30manuals/ ... 0R_C15.pdf
Pages 5, 6, 7 in that NC30 manual detail how to test the reg / rec also etc
Good luck!