If you are not a US citizen, look at Publ 519 U.S. Tax guide for Aliens first. Other publications of interest could be Publ 513, Publ 514, Publ 515, Publ 597 (for Canadians), Publ 901 (US Tax treaties).
If you are a US citizens or Green Card holder, look at Publ 54 Tax guide for US citizens and Resident Aliens Abroad and 593 Tax guide for US citizens and Residents Going Abroad first.




