How to wire a dual output power converter
Is -V Input the ground from the power source? what about common?


-V is the negative side of the power source.  It would be connected ground in most designs.
(But the -V doesn't need to be ground, strictly speaking.  If +V input were connected ground, and -V input were connected to a negative voltage, the converter would work just as well.)

Common is the point against which the outputs ar ereferenced.  Typically, it would be connected to ground on the other side of the isolation barrier.

 

Notice that ground symbols are different on the input and output sides.  -V and Common don't necessarily have to to be connected together, because this is an isolated DC-DC converter.