During summers last year(May - July 2007), I was in the US for an internship on an H-3 visa. I worked in NYC but stayed in NJ. I have received my W-2 forms. I want to know what all tax forms do I need to fill in order to file my federal and state tax returns. Am I eligible for 1040NR-EZ? Also do I have to fill both NY and NJ state forms. If yes kindly tell me which all forms are required and,if possible, provide links from where I can get those forms. Do i also have to fill the IT-2 form?

You can file Form 1040NR-EZ, but filing Form 1040NR is probably better for you, because you CAN deduct daily living expenses due to the short duration of your stay.

You will need to file Form IT-203 for NY and NJ-1040 for NJ on the state level, plus the various support forms to claim the credit for NY taxes paid on your NJ return.