I do books for both my boys in addition to annual family albums. I've done them in 3 year intervals (i.e. 0-2 yrs, 3-5 yrs, 6-8 yrs and have started 9 to ?? (probably 11) for my oldest). I've done it this way as I wanted to limit the books to about 100 pages each and those ages are kind of where the cut off fell. I figure the kids will be less cooperative for photos as they get older so I'll have less to scrap then and might be able to fit more years into a book.
I do a combination of pocket and traditional pages. The pocket pages start each year and include anything and everything, next is a birthday page, then a bunch of individual pages for significant events, milestones, holidays, interviews and just photos I really like that deserve a page to themselves. Then I repeat for the next year (i.e. pocket pages, birthday pages, other individual pages). The very last page of the book is a 'review' page, not of them, but of facts, figures and major events at home and around the world over those three years (price of petrol, food staples, postage stamps, major news events, popular movies, musicians, etc) - I think that would be interesting to look back on in 20 years time.
I have THOUSANDS of photos in their books. Doing pocket pages is the only way I could achieve this. In addition, I use photo collage cards (usually 4x6) to fill some of the pocket spaces, so I can fit even more photos in. There are some examples
here and
here. Traci Reed had some good ones too but I can't see them in the store anymore. Sometimes the pictures are quite small, but in the printed books (12x12) they look fine.