The general rule is: Educational expenses to improve your current job skills are deductible. But learning a new job is not. From JK Lasser’s Your Income Tax 2013, pg 580: "For a deduction, the courses must be related to your existing job responsibilities and not lead to qualification for a new business.
This doesn't come up very often because most people come out better with the Lifetime Learning credit or tuition & fees adjustment (“above the line” deduction), rather than taking an itemized deduction subject to the 2% of AGI Threshold. But you can do both if you tuition is more than $10,000.