Apply ITIN number for your wife. Your wife needs to fill up W-7 form. Send all your fed tax return documents with w7 form to address provided in the w7 instruction form. Since you will not be able to get the ITIN number immediately to meet deadline, you will have to send joint filing without your wife's ITIN number for state tax filing. When you send documents for state filing, the state will provide the temporary number but before submitting your docs for state filing call them and explain your situation.

Check the link below for further information.

http://www.irs.gov/individuals/article/0,,id=96287,00.html