Tip - Open the Appearance Editor and Edit CSS file to Change the Text Size & Fonts

1. Open the Appearance Editor and go to the CSS file
2. Change the Text Size and Font

Here is the link on Web Safe Fonts
http://www.w3schools.com/cssref/css_websafe_fonts.asp

Actually Brandon wrote a complete guide on it along with a video and PDF version to download you can refer to that also by clikcing on the link below.