I am working on L1A in US since 10th Nov'08.
My wife and daughter (born on 29th Dec'08) are in India.

The W2 form shows my status as Single.
How should I file my Tax return?

My wife and kid will join me in April, and I heard that they will require my tax filing details for applying L2 visa.
Please Help.

You can file jointly with your wife and you both CHOSE to be treated as resident aliens. This will allow you to claim the $10,900 joint standard deduction plus two $3,500 personal exemption (for yourself and your wife).

However, you CANNOT claim your child, because she spent NO part of 2008 in the U.S.

You will need to submit Form W-7 to apply for an ITINs for your wife. A notarized photocopy of her passport needs to be stapled to the W-7.

The downside is that:

• you must WAIT to meet the Substantial Presence Test before you can file, which means you must wait until 15 June 2009.
• you must declare ALL 2008 world-wide income, but you can at least partially offset any double taxation by claiming a Foreign Tax Credit (Form 1116).

Even with the downside, this is probably the best way for you to file.