It's a big project...I dont know how you'll make it short...but here's my suggestions.
essential:
In terms of LG15
1. Bree's background/personality (homeschooled, where she lived, age, etc)
2. Relationship with Parents
3. Relationship with Daniel (who he is, they like each other/kiss, they argue over religion)
4. Her religion (mention how she's devout)
---->a) Crowley Refereces
---->b) Biblionmancy
---->c) equinox
---->d) religious performances/plays
---->e) "not mainstream"
5. The ceremony she's preparing for (excersizes, diet, and such)
---->a) Iron pills/Shot in the arm/"Doesn't Bree look tired?"
---->b) The date 10-12-06
---->c) Yoga
---->d) Order of Denderah / Parents don't even know
---->e) Strange Language she has to learn (Enochian)
6. where she's at Currently in the story
In terms of Cassie:
1. where she was first mentioned, and what daniel/bree said about her
2. How her youtube channel has weird clues that are reversed sounds, negative images, morse code, coordinates, etc
3. some theories: is she dead? is she part of Bree? is she real?
4. summary of clues so far:
http://www.lonelygirl15.com/forum/viewtopic.php?t=809
(that'll help)
5. the latest poem...maybe an interpretation
(optional, but would be awesome if you added 'em)
Mysteries such as
1) the strange tags
2) the "Proving Science Wrong" theme