To add letters and text to your pattern, follow these steps:
- Click Pattern->Add text from the main menu.
- Type the text you want to add into the Text field.
- Optionally choose a font and size.
- Click the Add button.
- The text is now in the clipboard. Drag the text to where you want it in your pattern.
- Click Edit->Paste from the main menu.
- Click anywhere outside the selection to discard the contents of the clipboard.
There is also an instructional video that shows you how to do it here.