The IRS instructions for Line 22 (Supplies) say:
"You also can deduct the cost of books, professional instruments, equipment, etc., if you normally use them within a year. However, if their usefulness extends substantially beyond a year, you must generally recover their costs through depreciation." (see https://www.irs.gov/pub/irs-pdf/i1040sc.pdf). In this case, you would add the books as assets for depreciation.
Even if the book is useful for several years so you must depreciate it, you will probably be able to take the full deduction because it will probably qualify as a section 179 expense.
