Expose comes with a rich typography settings provide live preview to check the font before apply. The font list provide the list of fonts available from
Google Fonts and
General Font family. To work with this settings you need to select the font first and see the preview, if you are satisfied with the preview provide the right selector and Save.
Adding New Google Fonts
Adding new Google font is really simple. There is a gfonts.txt file under your
templates/TEMPLATES/ folder. You need to delete the file and browse the template settings page. Expose will then fetch all the latest Google fonts and re-generate the file again and you can see the fonts on font drop-down.