Where could I go to find some information on voluntary work to have experience in the field of computer tech.?

I am a college student in persuit for a career in computer programming but my counselor advised me that companys dont just hire out of the blue, that they look for specific training and experience. Well i was trying to find out if there was a site or information center where i could go see which companies would let me get a part time or even voluntary work to gain experience.