Complex sentence: Seaton began his career as a stage manager on the series "In the House", "Smart Guy", "The Jamie Kennedy Experiment" and "That's So Raven", He made his directorial debut on the latter series.
Split into simpler sentences: Seaton began his career as a stage manager on the series "In the House". He then went on to work on the series "Smart Guy", "The Jamie Kennedy Experiment" and "That's So Raven", He made his directorial debut on the latter series.