The Item Area is located in the middle of the Main Invoice Screen.  It looks like a small spreadsheet.  It's here that you enter the products that you are selling to the customer.

You can reach any of the help pages by selecting any of the sub-topics found under this chapter heading.

Additionally, we have prepared an illustrated guide to using the Item Area, and you may wish to have a look at it. You can reach it by clicking on this link: Entering Products on the Main Invoice Screen