For me, it's mostly about stories. So I just use whichever photos help tell the story best whether it's 1-40. Whatever works.
Then at the end of the year, I round up all the layouts and have the family help me decide which ones to include in the book. I think 07 was about 40. I haven't finished all of 08 yet.
I don't really worry about page coordination. i figure it it looks a little chaotic, it's just symbolic of our life.
HTH
Terri