Most Collection Quests begin by examining any of the members of that collection, which are harvested from special, random ground spawning nodes using the Collecting harvesting skill. Members of this collection can be found as follows:
Corpse Drops: Found as corpse loot on some or all mobs in the zone, or looted from Chests.
Harvestable Pages: A fluttering piece of paper named !.
All collection members are from corpse drops except as noted below:
Page 11: Drops from sattars, Evol Ew lizardmen, Tae Ew lizardmen, and Rallosians in The Feerrott and Alliz Tae lizardmen in The Trembling Lagoon. (Found one around 122,-6,145 on a Evol Ew Thulian neophyte, but YMMV.)
See this note about tome collections and page source data.