How to indicate if a new category is for business income and expense?

To be included in business reports (and I don't know where else) you have to assign the category to a schedule C tax line item number.  To check the tax line assignment open the Category list by either clicking on the Category Icon or go to Tools-Category List or Ctrl+Shift+C.  Then select the category and right click on it to Edit it.  Click on the Tax Reporting Tab and check the box for Tax related and pick a Schedule C: tax line item.