I've been in choir for about 4 years now.
I can sing. I perform and win contests and everything. but like choir music.
I really want my voice to be like Rock. My band plays rock, but i only do back up vocals.
What can i do?
i know vocal lessons obviously.. but any techniques or a website online that can help? Any software that will help you experiment with Rock vocals?
Thanks 
practice practice PRACTICE!!!
sing along to some of the all-time rockers (beatles, bob dylan, led zeppelin, elton john etc)
start writing songs and book some local gigs too, who knows, it could lead to stardom!