Click on the A| button in the Object Palette on the left. You will see a textbox appear on the slide. Drag the textbox to where you want to place the text.
In the Formatting Palette on the right set the font face, size, and alignment. The title and any headers should be centered, while paragraphs should be justified. The jagged right edge of left-aligned paragraphs creates an uneven, visually displeasing effect.
Type or copy-paste the desired text into the textbox.
If copy-pasting from several documents with different fonts, use Edit > Paste Special… > Unformatted Text.
Be sure to insert a descriptive title in large font (around 80 pt.) at the top.