I heard that you can deduct business books related to your business as an expense, where would I deduct that?

You would deduct these as a business expense on your Schedule C of Form 1040. There isn't an actual line item for "business books" but you can enter the expense under "Miscellaneous Expense", or as "Subscriptions", or even as an "Office Expense."

To enter this expense in Turbo Tax, follow these steps (here I am assuming that you are filing your business on Schedule C as a Sole Proprietor):

• Log into your tax return.
• Use the search box in the upper right hand corner. Type "schedule c" in the box and press enter.
• This will bring up the "Jump to schedule c" link...click that link.
• From here Turbo Tax will ask you some specific questions about your business. You'll be led through different screens asking you more questions regarding your business.
• Once you've answered these questions Turbo Tax will bring you to a screen to enter you income. This may be in the form of 1099s or no 1099s. 
• After you've added your income (or skipped that part) Turbo Tax will bring you to the screen for you to choose what expenses you would like to enter onto your tax return.