(From Life of Emerson)
"He went out early to hunt a thought as a boy might hunt a butterfly, and, successful, pinned the prize in his cabinet by entering it in his 'Thought Book.'"

These are the notebooks I recommend. Although I offer age suggestions for starting notebooks, I recommend you start keeping your own notebooks from the beginning so they can watch what you do. I like to use 1" binders I can insert pictures in. I used fine art images from the Art Renewal Center for the covers. Sam's Club and Costco have the best prices.

Memory Gems: (Age 3+ beginning with Mother Goose)
Poetry or other selections that have been memorized or that you want to memorize. 
Not organized in any particular way. Self-illustrated.

Literature Gems: (Age 4+)
Alphabetical divider tabs, arranged alphabetically by title.
Each page includes title, author, when book was written, time, and setting of story. You can also add a brief line about plot. Self-illustrated, use shrunk down illustrations from books, or just add designs for color. 
(You will find many of the illustrations from classics each month in Story Club)
Include stories or books that have 'gems' you want to hold on to.

Around the World: (Age 5+)
Dividers alphabetized by nation.
Include maps, pictures of crafts children make, paper doll costumes, recipes, holiday traditions, landmarks, foreign words, games, etc.

Books, Books, Books: (Age 7+ or when they start reading)
Divided by 12 months.
Reading logs found in Story Clubs.
Separate out Story Resource Guide by month and place in proper section.

The Story of the World: (Age 8+)
Two types of pages: People and Events.
Create landing pages that are arranged chronologically by birth year or beginning of even year. Use divider tabs for significant event pages. 
Each landing page includes: name at top of page, birth year in right hand corner followed by death year, country of birth and country most associated with, if different, brief statement of most notable accomplishment(s) underneath name.
Wikipedia is a quick resource for that.
Pictures sources: illustrations from old textbooks, fine art images, shrunk down illustrations from old children's books (available in Story Club resources).

Our Beautiful World:
Divider tabs: Stars, Ocean, Rocks, Plants, Birds, Animals, Insects, The Human Body.

"Heart" Journal: (10+)
A personal journal for reflective writing.

The Well Educated Mother's Heart:
Divider tabs: A Mother's Influence, Nature Study, Music, Art, Poetry, Storytelling, Imaginative Series, Heroic/Historic Stories, Writing, Math, Science, Joy.