I recently got Season 2 of this wonderful anime series, based on the light novel series of the same name. Season 2 adds 14 more episodes mixed in with those of Season 1. Season 2's episodes are supposed to be viewed interspersed with Season 1's episodes.
In fact, the first seven episodes aired for Season 2 were the 6-part The Melancholy of Haruhi Suzumiya followed by The Boredom of Haruhi Suzumiya. Episode 8 is the first actual Season 2 episode, Bamboo Leaf Rhapsody. Then the next three episodes are once again taken from Season 1: Mysterique Sign and Remote Island Syndrome Part 1 and 2. After that is the massive 8-part Endless Eight story, followed by the 5-part The Sigh of Haruhi Suzumiya, which rounds up the new episodes added this season. The rest of the Season 1 episodes are then aired after: The Adventures of Mikuru Asahina Episode 00, Live Alive, The Day of Sagittarius, and finally, Someday in the Rain.
As far as book adaptations go, this series is fairly well-done, with little to no changes made. Our point-of-view character is still the otherwise-unnamed Kyon who also narrates the novels in first person. Kyon's dry wit is an effective anchor against the craziness and chaos that Haruhi generates. In fact, there were some episodes in Season 2 that I could swear I've already seen before which is impossible, although explainable by the fact that I've already read the novels that have been localized so far.
I had a Haruhi Suzumiya marathon today, covering all six parts of The Melancholy of Haruhi Suzumiya. Already, I am reminded just how fun reading and watching this story has been. Hopefully, I'll find more time tonight or maybe tomorrow to view the rest of the series.