As a spinoff to this question: Incorporating research and background: How much is too much?
I'm writing a middle-grade fantasy novel with a historical fiction component based in Ancient Egypt. I'm doing enormous amounts of research on both the history and the religious aspects (it's based on the Exodus). A lot of people seem to think my research would be of interest to people and have suggested I consider a companion book and/or a blog.
Obviously I don't want to take away writing time for my novel. I have to finish it first. But the longer I wait with research notes, the more I forget the details. Writing everything down takes a while.
Has anyone done this or seen this done (especially not by hugely popular books/authors...I mean, let's not count A Song of Ice and Fire)? Is it just another time sink to slow down finishing my novel? Or is it worthwhile?