http://forum.bandamp.com/Lessons/51554.html

and by the way, you have to get over yourself when it comes to being embarrassed to sing when other people are around. if you need to go get a sound proof bullet proof pressure locked steel vault to practice singing in, do it, but realize that some day you'll have to sing in front of someone if that practice is going to be worth anything.

my suggestion: get over it sooner rather than later. this is really one of the trickiest things about singing, getting over yourself. i don't really have any particularly good tips or tricks other than explaining over and over how it's not a big deal.

try going to a karaoke night somewhere. you don't have to sing to become quickly not embarrassed with your own singing skills. but if you can make yourself get up there and sing, then all the better.