X-Men: Schism

Quite a good and well-thought out storyline, although you can safely skip the Prelude volume.

It fits into the regular timeline here.

The End of an Era:
X-Men Legacy #258 [1] X-Men Legacy: Five Miles South of the Universe
New Mutants #32 [1] Fear Itself: Wolverine/New Mutants
Astonishing X-Men #43 [1] Astonishing X-Men, vol.8: Children of the Brood
X-Men #19 [1] X-Men: FF
X-Force #18 [1] Uncanny X-Force: The Dark Angel Saga, Book 2
Prologues:
Prelude to Schism #2 [2] X-Men: Prelude To Schism
Prelude to Schism #1 X-Men: Prelude To Schism
Prelude to Schism #3 X-Men: Prelude To Schism
Prelude to Schism #4 X-Men: Prelude To Schism
Schism:
Schism #1 X-Men: Schism
Schism #2 X-Men: Schism
Schism #3 X-Men: Schism
Generation Hope #10 Generation Hope: Schism
Generation Hope #11 Generation Hope: Schism
Schism #4 X-Men: Schism
Schism #5 X-Men: Schism
Epilogues:
X-Men: Regenesis [3] X-Men: Schism
Generation Hope #12 Generation Hope: Schism
X-Men Legacy #259 X-Men Legacy: Five Miles South of the Universe
X-Men Legacy #260 X-Men Legacy: Five Miles South of the Universe
Wolverine #17 Wolverine: Goodbye, Chinatown
Wolverine #18 Wolverine: Goodbye, Chinatown
Wolverine #19 Wolverine: Goodbye, Chinatown
Wolverine #20 Wolverine: Goodbye, Chinatown
New Beginnings:
Uncanny X-Men #1 Uncanny X-Men, vol.1
X-Men #20 [5] X-Men: War Machines
X-Force #19 [5] Uncanny X-Force: The Dark Angel Saga, Book 2
Wolverine and the X-Men #1 Wolverine and the X-Men, vol.1
New Mutants #33 [5] New Mutants: A Date with the Devil
Astonishing X-Men #44 [5] Astonishing X-Men, vol.9: Exalted
Avengers Academy #22 [4] Avengers Academy: Second Semester
Avengers Academy #23 [4] Avengers Academy: Second Semester
X-Men Legacy #260.1 [5] X-Men Legacy: Back to School

Footnotes:

  1. Last issue of regular series prior to the event.
  2. Yes, these issues are listed out of order, because chronologically, that’s how it works. For no readily apparent reason, as it makes no difference whatsoever to the story.
  3. Some, but not all, of Generation Hope #12 is reprinted in X-Men: Regenesis.
  4. After the events of Schism, X-23 becomes a regular cast member in Avengers Academy.
  5. First issue of regular series after the event.