Student loan interest is probably the most common deduction taken at our VITA site.
It is an "above-the-line" deduction (officially called an "Adjustment to Income"), which means it can be taken even by taxpayers who do not itemize on Schedule A.
You can report up to $2,500 of interest paid on a student loan on line 33 of Form 1040. It is important to note that you don't get any deduction until you actually start paying back the loan, and even then you only get to deduct interest paid, not principal.
More information on the student loan interest deduction is available in Pub 17, here.
And even more information on the student loan interest deduction is available in Pub 970 here.