Congratulations on your drive to get past stage fright...

A quick search online should find you some tips and ideas to get rid of stage fright... I have seen a few in the past.

Apparently, after a certain number of times (I can't remember the number), it becomes just about natural and you just worry less.

Remember to have some fun - learning relaxation techniques can be useful not just for stage fright but to help you relax generally (I always liked that book Don't Sweat the Small Stuff).

I know the tips above are sort of general but I hope it helps point you in the right direction.

As to vocal exercises - the best exercise is to practice... It's sort of tacky but - your voice is your instrument. Getting to learn its possibilities and limitations will definitely help. Again, a quick search online can find you some ideas - I've seen a few resources specifically for this in the past, too.

Best of luck!