Some people can sing naturally, and others require voice lessons. In an old band, we took voice training, and it worked great. Our other guitarist brought a guitar along and transcribed vocal melodies and harmonies on the guitar, so we knew what each part was.
Basically, lessons consisted of warm up, scales, and practicing tunes that we liked to sing. Having a coach there to point out the little sharps and flats was great.
Guitars:
Fender 2006 MIM Fender Stratocaster HSS in 3TS
Ibanez RG 570 with a bridge Invader
ESP M II Deluxe with a Tune-o-Matic bridge
Eleanor, the magical, mystical Road Worn wonder Tele
Blackstar HT Club 40