Reading books and watching DVDs are not always leisurely pursuits. Investing the time in watching an instructional DVD or reading a non-fiction book could increase your knowledge in a variety of subjects. Perhaps the knowledge you gain proves extremely helpful in the performance of your job. By the way, anything purchased for legitimate business-related purposes is viable as a tax deduction. Claiming tax deductions on DVDs and books, however, does require a little extra accounting work in order to defuse any skepticism on the part of a tax examiner.