learning microtonal music

now im new to this microtone thing
lets say i want to learn some non21tet music (on fretless guitar or what not)
should i use some sort of tuner at first to get the exact pitches right
or mark out spots on the fretboard etc....
or does a different approach lend itself to diff music?
and what would be some good music to start with?

thanks a ton
rodrigo