Important episodes to watch to jump on the show

Simple question, and expecting a list of episodes: I have not seen Arrow AT ALL; wanted to, but didn't. I cannot watch the entire two seasons, due to the short time I have (school, work, life, laziness). To prepare for season 3,

what are the important episodes to watch to prepare for season 3, that I can understand and won't be confused by because an episode isn't on the list (or something).