If you're interested in becoming a Chronicler, contact Shikari or Drocilla in-game via an OOC message to express your interest, and let them know what sorts of areas you'd like to contribute to. The ultimate decision of who will be a chronicler is up to them, and not everyone who applies will be chosen. Note that there is no pay or reward for this; you're just helping provide a resource of value to everyone in Lusternia.