Leslie,
That is one area we are still pondering. I used a Sonlight timeline for my oldest son for his first 4 years of school, and we found that his grasp of time really wasn't much enhanced by keeping a timeline book. We were very diligent about doing all of the entries. Listening to Diana Waring's "What in the World" CD's was actually MUCH more beneficial in helping him get the flow of when things happened (which is why you'll see that resource in our upcoming Ancient's guide).
In our previous guides, we've gone with a more straight-forward "see-the-flow of time" style timeline (which is actually what CM recommended prior to keeping a Book of Centuries).
We are currently weighing whether to get into the more involved Book of Centuries as CM described or to go with a different approach. Fancy timeline books and stickers can really add up and become a costly addition to a program, so we're more likely to go the cost-efficient route with a do-it-yourself method.
Sorry I can't be more specific yet!
Blessings,
Carrie