I cam to US (H1B visa) for first time in February 2010 and my wife and kid joined me in US (H4 visa) during September 2010.

1) Can I file as "married filing jointly" and apply for ITIN for my wife and kid when I
File Tax for 2010?
2) Can I include my child as dependent when we file taxes for 2010?
3) Do I need to include my India Income for January and February in US return?
4) What deductions can be claimed as I am the only earning member and supporting wife and kid?

1. Yes
2. Yes
3. Yes. Also claim earned income exclusion or foreign tax credit. Your U.S. Tax Return: U.S. Citizen or Resident with Foreign Income (http://taxipay.blogspot.com/2008/03/us-citizen-or-resident-with-foreign.html)

4. File joint return. You get all the benefits. Your U.S. Tax Return: The U.S. Visas (http://taxipay.blogspot.com/2008/08/us-visas.html)

Thanks for your help.