1. Apply for a SSN for ur wife. Social Security will then refuse and give you a letter stating that they cannot issue SSN for a H-4 person. Take this denial letter to the DMV.
2.Take 2 proofs of your residence...Utility bill, telephone bill, lease agreement etc.
3. Her visa balance period on H4 should be greater than 1 year, otherwise states like PA will not issue licence.
4. Her passport and I-94.
5. Employment letter from your employer (H1 principal) on company letterhead...Faxes not accepted.