If you were reccomended for admission, all you have to do is send the Graduate Admissions Office evidence of adequate funding for the living expenses and health insurance of your dependent(s), we will issue dependent I-20's for your family. See http://admissions.osu.edu/apps/pdfs/ig-affad.pdf

The U.S. embassy will issue F-2 visas to your spouse and children if you present the dependent form I-20 and proof of financial support for your family.