Help with singing? HELP! :)?

Hey, im really interested in learning to sing better. I play guitar and me and my friend like to sing for fun but anyway i need some tips. I know nothing right now, keep in mind. I mean we just sing on a fun, casual basis when I play the guitar. But her dad has a small recording studio and she wanted to record a song (she's a pretty good singer). Anyway, I need some breathing tips and vocal excercises for a total beginner. And maybe name some good books or websites that can help. My mom's not gonna wanna pay for vocal lessons coz i already do guitar and art. So any tips or vocal excercises for a beginner? THANKS!