Diablo – find Leah’s journal

I found the report on a dead body named Wortham Villager Corpse, he was very well marked and appears to be a non-random encounter. It was just prior to getting to Leoric's palace as @Alok mentioned, in the Northern Highlands.

The Villager’s Journal spawns in a Old Keepsake Box at the Old Ruins, it was previously reported in The Lyceum a random dungeon whose location is discussed in this thread. It was unobtainable prior to patch 1.0.3, which led to most of the confusion around it but it is now dropping again.

According to this forum post and my own experience, they are located as follows:

Judge of Character

• Fuad's Journal - In the random location Fuad's Cellar in Howling Plateau, kill the Unique enemy Fuad and he drops this.
• Zoltun Kulle - In the Hidden Camp, once you begin Betrayer of the Horadrim, it will be on the ground beside Adria.
• The Musings of Sardar - In the random location Tomb of Sardar in the Dahlgur Oasis.
• The Promises of Fezuul al-Kazaar - Kill the unique Grotesque Fezuul that spawns at a randomly occurring puddle of water with a number of bones in the Dahlgur Oasis. It spawns after you kill the skeletons that will spawn upon investigating the bones.
• Eirena's Journal - Eirena, after the conversation Eirena's Journey available throughout Act II so long as Eirena has been out of the party at least once.
• Iron Wolf Captain's Journal - On the northern part of Alcarnus, you will find the Iron Wolf's Captain's Corpse which will drop this journal.
• The Legend of Zei the Trickster - Shen, after his conversation A Case of Mistaken Identity which is available from the start of Act II.
• Kala's Poem - Kala (North side of Hidden Camp), after her conversation Noble Dreams from the end of Betrayer of the Horadrim and during the quest Blood and Sand.
• The Last Will of Khan Dakab - In the random location Tomb of Khan Dakab in the Dahlgur Oasis.
• Larra's Diary - In a random Deserted Cellar with the merchant Larra in Black Canyon Mines after you talk to the merchant Larra who appears there. (seems to be always the northern cellar)
• Kulle's Journal Part 1 - At the End of Vault of the Assassin.
• Kulle's Journal Part 2 - At the start of Cave of the Betrayer Level 1.
• Kulle's Journal Part 3 - At the end of Cave of the Betrayer Level 2.
• Kulle's Journal Part 4 - Drops from the defeated Zoltun Kulle in Archives of Zoltun Kulle.
• Leah's Journal (8-12) - Right side of the Hidden Camp during major missions. Certain ones are available during certain quests..
  • Part 8. During Shadows in the Desert.
  • Part 9. During The Road to Alcarnus (from Find the Khasim Outpost) & City of Blood.
  • Part 10. During Unexpected Allies & Betrayer of the Horadrim.
  • Part 11. During Blood and Sand & The Black Soulstone.
  • Part 12. During The Scouring of Caldeum until the end of Act II.
• The Seven Lords of Hell, Belial the Lord of Lies, Azmodan the Lord of Sin, Diablo the Lord of Terror, Andarial the Maiden of Angish, Duriel the Lord of Pain, Mephisto the Lord of Hatred, and Baal the Lord of Destruction - Cain's Lost Satchels throughout the act. The books are sequenced and it doesn't matter where you pick them up.
  • I just did a playthrough of Act II and I've seen them in:
    • near the ceremonial circle in Secret Altar (Howling Plateau),
    • south of the Khasim Outpost waypoint,
    • the random dungeon The Ruins Levels 1 and 2 (Stinging Winds),
    • The Crumbling Vault (and Vault Treasure Room)(Stinging Winds),
    • south of the Road to Alcarnus waypoint,
    • north west of the merchant in Flooded Causeway,
    • Ruined Cistern,
    • east of Path to the Oasis waypoint,
    • The Forgotten Ruins,
    • Vault of The Assassin.
  • I also recall finding them in some of the non-cave (in appearance) dungeons during previous playthroughs such as:
    • Chamber of the Lost Idol(Stinging Winds),
    • Tomb of Sardar(Dahlgur Oasis),
    • the Tomb of Khan Dakab(Dahlgur Oasis).
• A Love Letter - Dahlgur Oasis, Keepsake Box
• Necromancer's Log - Stinging Winds in a random event location, after you complete the event The Restless Sands, Mehtan the Necromancer will drop this.
• The Imperial Guard's Orders - From an encounter in Dahlgur Oasis or one of its cellars.
• Crumbling Journal - You collect this from Skeletal Remains in Desolate Sands.
• Poltahr's Notes - In the random location Chamber of the Lost Idol in Stinging Winds.
• The Ancient Portal Device - Beside the Ancient Device that can randomly be found in Desolate Sands.
• Blackened Journal - From a Charred Iron Wolf Corpse on the west side of the Caldeum Bazaar that can be found during The Scouring of Caldeum.
• A Servant's Journal - From a Crumpled Corpse on the north side of the Caldeum Bazaar until the quest Unexpected Allies.

Historian of Caldeum

• The Desert Aqueducts Part 1 and Part 2 - In Western Channel and Eastern Channel of the Hidden Aqueducts. These are sequenced so it doesn't matter which satchel you find first or if you find the same one twice.
• An Abridged History of Caldeum (6) - Searing Sands Inn in the Caldeum Bazaar. These books become available as you complete the main quests. If you miss any, they will all be included with the drop of the next one you collect.
  • Part 1: From the start of Act II onwards.
  • Part 2: From The Road to Alcarnus objective Find Khasim Outpost onwards.
  • Part 3: From A Royal Audience onwards.
  • Part 4: From Unexpected Allies onwards.
  • Part 5: From Betrayer of the Horadrim onwards.
  • Part 6: From The Black Soulstone onwards.
• The Dahlgur Oasis - Dahlgur Oasis, Keepsake Box.
• On the Desolate Sands(3) - Desolate Sands, Traveler's Pouches. These are sequenced so you will always get these in order.
• The Chamber of Faces - Dahlgur Oasis, right outside the random location Tomb of Khan Dakab.

Eavesdropper

• Guard's Orders - Imperial Guard Supplies in Khasim Outpost.
• Proclamation from the Imperial Guard - In the south of the Caldeum Bazaar, just outside of the Hidden Camp entrance during A Royal Audience.
• Missive to Maghda Part 1 - Tortured Cultist Courier at the back of The Secret Conclave in Howling Plateau and/or Sandy Cellar in Alcarnus.
• Missive to Maghda Part 2 - Tortured Coven Minion Alcarnus, just south of Maghda's Lair.
• Deciever's Orders Part 1 - Envoy of Belial found in The Sewers of Caldeum.
• Deciever's Orders Part 2 - Envoy of Belial found in Dahlgur Oasis.
• Deciever's Orders Part 3 - Envoy of Belial found in Desolate Sands.
• The Feared Hero - Stinging Winds, random spawn of a cultist camp after the Khasim Outpost.
• Hunter's Journal Part 1 - At the start of The Forgotten Ruins.
• Hunter's Journal Part 2 - Hidden Aqueducts (Western and/or Eastern Channel)
• Hunter's Journal Part 3 - Beside the entrance to Archives of Zoltun Kulle in Desolate Sands.
• Hunter's Journal Part 4 - Beside the Shadow Lock in The Storm Halls in Archives of Zoltun Kulle.
• Hunter's Journal Part 5 - Beside the Shadow Lock in The Unknown Depths in Archives of Zoltun Kulle.
• Hunter's Journal Part 6 - Drops from the guardian in The Forgotten Ruins that spawns after recovering the head of Zoltun Kulle.