Jacquelyn,
We begin with Charlotte Mason's suggestion for a column timeline in Beyond and Bigger because kiddos don't really have a good grasp of the flow of history at that age and seeing events in 50-100 year columns on a single or a double page really helps them get a better feel for the flow of time.

After that, we move into our one year overview of world history with Preparing Hearts and step the timeline up a level to either a wall timeline or an accordian-folded timeline. This also is designed to give a feel for the major events in the flow of history, providing mental pegs for children to hang their history readings upon in the future.
Once we move to CTC, we begin a chronological flow to history using a 4 year cycle. At that point we do begin a continuous timeline, which will be added to each year. However, we do not do it in isolation but rather within a beautiful full-color Student Notebook that provides a deeper look at those timeline entries by providing places for written narrations, copywork, sketches, common place book entries, project work, and maps (in addition to the timeline). This makes for many connections among the history-related work and keeps the timeline book from being a separate book unrelated to the rest of the children's work. The student will add a new section to the Student Notebook each year (through each guide) until there is one large volume completed over 4 years.
On a sidenote, we did have our oldest son keep a separate timeline book for his beginning 5 years of schooling with cut and paste figures, but we have since found much greater retention and connectiveness when we switched to the method we're using now (both with our oldest son and our upcoming kiddos). Drawing and labeling the figures really helps cement the people and events in the kiddos' minds. It forces them to interact with the material more and makes it personal (and also very engaging to look at)!

My boys are much more invested in their timelines now, then they ever were when someone else had done the drawing and labeling for them. It means more to them because of the work it has taken to produce.
Blessings,
Carrie