I created a bible for my 2010 NaNoWriMo project,and am very glad that I did. It allowed me to keep track of characters,the significant people in their lives, how they interacted, what defined them, and the sequence of events (past and present). It also allowed me to note how I had described things like cars,rooms, restaurants and such. As my characters moved in a very luxurious lifestyle, I needed to keep track of things like jewelry, designers,and the worlds of art and music.
A good bible can help prevent some very embarrassing mistakes, and is well worth putting the effort into.
(c) January 2011 Bonnie Cehovet