Congratulation for American son (trying to be sarcastic, but it is not funny right?)

If I were you, I will visit to nearby  H&R Block office. March madness
will be starting soon and they will be hungry to fill in their time card. Ask
them if they do NR? If they do, they will give your result instantly and will
be answered all your questions without paying a nickel. Do not hesitate
to  walk out of office, say, I will think of it. One Latino visited 4-5
near by H & R Block Tax office just to gather all information , what answer
needed to be said yes and no so he can get the maximum refund.

 Last year I found couple web sites for NR tax services. By the way, did you participate on tax seminar launched by your school? Most school provides tax help and you would have got your answer too.

I heard if you itemize ( NR case), will give more tax return ? So do not forget to ask what are the itemize deductions are? ( H and R may not have this answer for you)  It is good to know all the options and get the most benefit. 

I'm not a lawayer. you should be able claim the dependent exemption, even if your son was not born in the U.S.A.  If you want reliable answer you can visit the nearest tx filing services such as H&R or jackson hewitt