HI,

I have started working in a us company in New York on September 1st 2008.

I am under a j1 visa of 1 year

I a from france and my income is 45000$

My questions are the following:
What can I claim/expect as tax refund...
Which expenses should I deduct (rent/plane tickets/ telephone... )
What papers do I need to fill for taxes
What is the deadline

Thank you in advance for yor precious help

On J1 you are exempt from residency for 2-years. You must file non-resident tax return and Form 8843. Your income is not subject to FICA taxes. You will only report the income you earned while present in the U.S.
Read: Your U.S. Tax Return: U.S. Tax Filing Requirements for Non-Residents

Further, if your J-1 tour is ONLY one year, then the J-1 tour is considered to be a temporary job assignment by the IRS, so you can deduct your daily living expenses (rent, meals, transportation, travel, incidentals) as an itemized deduction using Form 2106, privided you are NOT being reimbusred for these costs with a tax-free stipend from your employer.

You will need to file For 1040NR plus Form 2106.

If you need professional help filing this tax return, contact me at [email protected].