the best advice i give people who struggle with singing is KEEP SINGING EVEN IF YOU **** UP! My first song i learned to sing while playing, ( ripple ), I screwed up a few times with the words ( when i screwed up on the guitar ) but after a few times i said "hey if i get the guitar part wrong, well **** that im tryin to learn how to sing while playing, not play while playing. so i kept singing, ignoring mistakes ( as all professionals do ) and i learned to sing and play guitar rather quickly. actually, in 3 days.