Currently, our timelines are a bit of a mess, especially when it comes to "Appearances" sections. Some overlapping sources don't seem to have a fixed chronology, and some more vaguely-placed sources (e.g. Battlefront) usually end up all over the place.
So, I thought it might be a good idea to try and establish placements of troublesome sources. I'll list a few I've come across, and try to confirm their placement, then more can be added. I'm also trying to create an accurate timeline of Clone Wars material here - \\Captain Kwenn// — Ahoy! 13:31, 28 January 2007 (UTC)
Currently the chapters are placed under the Clone Wars header, but the episodes take place at different points on the timeline, so this is not practical. Chapters 6 and 7 occur prior to Republic 51 (when Ventress first fights the Jedi), while the remainder of Season I take place following Republic 53 and ending with Chapter 21 prior to Jedi: Shaak Ti (as 21 begins where 20 left off, even though the remainder of the episode takes place following Jedi Trial). Chapter 22 is set after Jedi Trial and Dreadnaughts of Rendili, since Anakin is both a Jedi Knight and has his scar. The final three episodes occur prior to RotS itself, though following the start of Labyrinth of Evil and The Siege of Saleucami.
To reiterate: Clone Wars chapters should not be placed under a sub-heading
The earliest campaign is that of the Gungans, beginning at circa 3032 BBY, meaning the game begins within 1,000 years of the KotOR games - not during the Rise of the Empire era, as it's often placed.
Although this is currently part of the GB article, it should be treated separately (as is Forces of Corruption to Empire at War). Its Separatist campaign begins the game, with a prologue in which Dooku states he is leaving for Geonosis. Thus, the game likely starts at some point during the events of Episode II, prior to the battle itself.
The campaign - the only canonical element of the game - begins during the Battle of Naboo, so it should be placed after Episode I and all its variants.
The campaign - as with the first game, it being the only canonical element of the game - begins with its training prologue set during the Battle of Geonosis, so it should be placed after Episode II and its variants; between Machines of War and Most Precious Weapon.
The opening chapter is set while Obi-Wan and Anakin are en route to Ansion, meaning the novel begins at least prior to Chapter 2 of The Approaching Storm, and thus shouldn't be placed immediately prior to or following the film.
Although the story mainly focuses on Boba's story through Episode II, the book begins at some point before the film, as it includes not only references to Zam on Kamino, but also features the meeting between Jango and Dooku that leads to Jango taking the Amidala mission, and sees him leaving for Coruscant to rendezvous with Zam. Thus, it should be prior to the film itself.
The intro plainly states the book starts at 10 months after Geonosis, even though the Dinlo mission takes place (IIRC) at 12 months after. This means it should be placed between The New Droid Army ( and Hero of Cartao / The Cestus Deception (12 months ABG)
The game begins following the destruction of the first Death Star, so I'm assuming it's roughly 0 or 1 ABY, though I've commonly seen it placed all over the timeline.