Agree with 1010.It is the best way if you know where you want to apply.
Or if you are not familiar with the universties and institutes in USA.You might want to try these:
1.You may look through the major journals in your industry or academic field for postdoc position opennings and research faculty openings.
2.Go to the the website of universities that you are interested in. Look postings in human reasource page.