The Text tool (symbolized by A) allows you to insert text into an image. Click to draw a box that will contain your text (the box will be invisible after creation).
The Text tab in the Text properties dialog allows you to set the text contents of the box, along with color and alignment options.
The Pen tab in the Text properties dialog allows you to set options for the width, color, and style of that box.
The Brush tab in the Text properties dialog allows you to set the type and color of the brush that will fill in that shape.
The Font tab in the Text properties dialog allows you to set the font for that box.