Since you're self-employed I assume you also complete a Schedule C.  If you use Turbo Tax step-by-step to complete Schedule C you will be asked to enter the amount of your qualifying health insurance premium(s).  To the extent that you show a profit in your business, this amount will be carried by Turbo Tax to Form 1040 line 29.  On this Form this amount is subtracted from your total income.
If you pay health insurance premiums for your spouse/dependents you may also be able to deduct their premium(s).  Check that out in Turbo Tax.