ALL international students, regardless of whether or not they have earned money in the previous fiscal year, MUST complete and send in an 8843 tax form. There are NO exceptions. All international students in the USA are required to submit this form. The form and instructions can be found online at www.irs.gov.
Those students who earned money during the fiscal year are required to complete a tax form. There are two websites available which deal directly with international student returns. Please visit http://www.nrtaxreturn.com. Both sites will have all of the information you will need to complete your return.
The deadline for filing your taxes is around April 15th of each year.