I recently finished a 6-week commercial voiceover class with the incredible Roger Becker, casting director and teacher extraordinaire of VO Syndicate.
I can't recommend this class enough if you're looking to break into the voiceover business. Roger is both an expert teacher and a beaming coach rooting you along from the sidelines. He works in-depth with his actors on each piece of copy until he's finessed it to perfection, giving his ingenious insights so quickly there's barely enough time to write it all down.
This class is invaluable to anyone looking to get a start in T.V. and radio voiceover work. All the info at: vosyndicate.com