I bought the Lost Encyclopedia (of course I did). It's official and shit, so it gives a few notes here and there that weren't necessarily made clear on the show (or weren't at all).
Here's some stuff I found interesting. I'll keep updating... really for my own records. But if anyone else wants to read and comment, boy that'd be swell.
Epilogue: I also read the "epilogue" of the book, it goes over the major characters in the sideways world, with some pictures, a few quotes and what their sideways journey was all about. A few interesting notes:
Sayid: Why Shannon woke him up... the love with Shannon allowed him to be the man he wanted to be. (Posters note, haha: It makes sense to me. Sayid had so much baggage and memories of the terrible life he used to lead and Nadia (not her fault but...) was a constant reminder of that. The relationship he formed with Shannon wasn't based on anything but his character)
Jack: I posted anout this one before, but the entry discusses David a little bit, and just that his upbringing was VERY similar to Jack's. (makes me think David was just a younger version of Jack so he coudl work out his father issues.)
A -
Ajira Flight 316: confirms that it was Widmore's goons that murdered the remaining passengers left on Hydra island.
Annie: Annie left the island during the women and children evacutation.
Ash: The ash circle around the cabin was broken at an undisclosed time, and it WAS used by Jacob, but after the circle was broken, the Man in Black began to use it. Ash was also used in the Sayid/Dogen tests.
B -
Ben: The "rules" Ben spoke to Widmore about in his London penthouse were to never harm each other or their families.
Blast Door Map: There's really a ton of little things here but here are a few:
The ? on the map was due to Radzinksy (R) not knowing who occupied the station.
R did not know what was going on at the Orchid
After the Purge R survived and marked the stations he could get to with the quarantine sign, and took refuge in the Swan.
The CVs that are all over the map refer to a Cerebrus Vent the name DI used for the smoke monster.
Bram: again mentions that they went to the Cabin to find Jacob but realized MiB had been using it so they burned it.