According to their latest product blog post Google Docs, which is now a part of Google Drive, now has more than 450 fonts available to all users. To access all of these new fonts select “add fonts” from the bottom of the font selection menu that you’ve always used. Selecting “add fonts” will open up a new menu in which you can mix and match fonts to your heart’s content.
The fonts are in Google Drive (Doc) once you creaate a Document. Use the drop down arrow next to the default font–Arial–and the last choice is “add fonts.” You can explore to your heart’s content and add fonts to your Google Doc collection. But are these additional fonts also available in Google Sites? I checked the font drop down menu there, and did not see an “add fonts” option.