I've always enjoyed keeping a journal. That's what I called it anyway until an 'experienced' wiccan corrected me and explained that no, it was a Book of Shadows. So now I know.
The first jour- whoops, sorry, Book of Shadows (from now on referred to as BOS) was when I was about fourteen, and I tried to get family members (mostly practising witches, although they would rarely admit it) to contribute. THey smiled a lot and promised they would help, but ultimately all I got were two recipes involving vinegar and onions. (And I suspect that one of those was a fancy version of pickled onions)
Maybe I was wrong to ask - after all, should we really contribute to other peoples BOS? Personally I don't think there's anything wrong with contributing the odd useful hint or tip. The world would be a funny place if we didn't share. But the real problems come when people expect you to write your BOS for them. Maybe that's why my family wouldn't help all those years ago, they wanted me to write my own book instead of relying on them.
I still tend to think of my BOS more as a magical journal. I usually get through one per year and use a hard backed notebook rather than a loose leaf file. What you put in it is up to you - don't let anyone tell you there's a special formula cos there isn't. I've seen old, handwritten cookery books that have entries worthy of a BOS and some so-called BOS that contain nothing more than some (very bad!) poetry.
Brightest blessings
Tylluan
http://seekingthegreen.mysite.wanadoo-members.co.uk/index.jhtml