I have to pay an annual membership dues for my business, where should I enter this?

[Critter]

There are 17 unique categories for entering business expenses in the TurboTax Home and Business program for a Schedule C.  If you have a particular expense that does not fit in the other 16 categories listed use Other Miscellaneous Expenses at the bottom of the list.

[Carl]

Assuming you're self employed and that's what you're referring to with "my business",  in the Business Expenses section elect to start/update Other Common Business Expenses. Then scroll down to Legal & Professional Fees and enter it there.