Drag and drop audio to MIDI track works fine. But I'd highly recommend listening to the vocal melody line first played on a synth horn or piano before printing or exporting to notation software.
 Best audition solution for those who don't know how to sight read music.
 
 
For optimal results use a MONO vocal track with all time based (reverb, delay, flange, chorus) FX turned "OFF" Pitch correction software plugins (Antares Auto Tune, Waves Tune Real Time) are a definite + and a must if already use on the vocal track. But if you don't have any PC plugins, always run Melodyne pitch correction first.
 
 Keep in mind that during the conversion process Melodyne is going to Quantize notes from audio to MIDI so there may be, but not necessarily be some notation differences in places here and there during complicated vocal phrases where "ghost notes" and "accidentals" have been used. If you know what these are you can delete the blobs if necessary in Melodyne.