http://danoday.com/10-second-radio-commercials How to write 10-second radio commercials, taught by radio commercial expert Dan O'Day. Many examples of effective copywriting for 10-second radio spots.
http://danoday.com/voiceover-text-analysis Text analysis is the most vital skill for voice overs. Christine Coyle (Radio Ranch) demonstrates how to get the most of your voice acting audition copy.