M.L.
Join linkedin.com also, a lot of college alum societies have get togethers and websites you can network together on there. I was reading an article about this as well recently that said go to your alumni socials and ask around if anyone has heard of any openings or know anything about if their company was hiring.
You would be surprised, a lot of people have major school pride and will respond positively to someone they shared a school with.
You can just call or email and say, "I was looking at the almuni association for our school, xyz, and came across your name. I greatly respect and interest in your field. I am currently seeking employment in this field and would like to know if you know of any leads."
This link tells more on the actual etiquette of finding them for their particular college, contacting them by their preferred method and such, I really think it will help you. Your school should have something similar:
http://friarlink.providence.edu/networking_tips.php