Get your taxes done using TurboTax

In the Step-by-Step mode, type 'schedule c' in the Search area (magnifying glass at the top right), then click on 'Jump to schedule c'.

EDIT your Business.  Scroll to Business Income and choose START or UPDATE.

Click Start or Update under General Income on the next screen (screenshot).

On the next screen, you can add income from cash, checks, credit cards (screenshot).

Click this link for more info on Reporting Business Income and Expenses.