Here's what I did:
First I downloaded a font-face kit from Font Squirrel [http://www.fontsquirrel.com/fontface]. I unzipped it and put the stylesheet.css file in my themes css directory [themes/myTheme/css] and the font files into a directory I created in my theme path [themes/myTheme/fonts].
I then edited the stylesheet.css file and inserted the relative path to the font directory into all the url properties [url('../fonts/fontname_-webfont.eot'); etc.]. I also made note of the font name used in the font-family property.
Then, within my layout.css stylesheet [themes/myTheme/css/layout.css] I inserted '@import url("stylesheet.css");' at the top.
After that all I needed to do was add the 'font-family' property using the font name from stylesheet.css to whatever style selectors I wanted to change.