I too agree with Greg. The only thing I'd add is that I'd give more emphasis to the shorter, more intense intervals to boost 1 and 5 minute power. In my experience it is rarely the sustained efforts close to threshold that drop the newbie (especially if they know how to draft), it's more their inability to hang in on the hills, or to make the repeated hard effort accelerating away from junctions etc. Being able to hang tough for a very few minutes at a time, and then recover as the pace eases slightly, makes all the difference.