A sponsor is an employer who can demonstrate to the government that the skills you offer are scarce in the U.S. In the past 5 years this has become more difficult to do. The only ways I've seen this happen are through personal/social/family networking.
Visa status is one of the few criteria that a U.S. employer use to legally discriminate against job applicants, so it might be difficult to find a job here first. Best advice I have to give is to inquire about it through any professional contacts you have - or to try applying to some jobs in the U.S.