Other than Britnell, Waldron, and Rod & Staff products, these are all free resources:
For toddler/preschool, I like "Rainbow Lessons" by Jane Britnell. There are two books, a year each, for OT and NT. I like Britnell, but I don't actually use it. I create a storybook of the Bible at the preschool level using construction paper and markers in a binder. I draw the stories (stick figures) and write the text, along with a memory verse for each lesson. It takes about 2 years to get through the Bible that way. I also like reading aloud from the Rod & Staff story books (meant to be a reading curriculum for 2nd-4th grades). For late preschool through elementary, I like
this and
this, as well as the R&S readers I mentioned earlier. For middle school, I like R&S Bible (all of it... the books don't increase in difficulty as the grade level goes up... they just take you through the Bible, so all are appropriate for middle school), and
this. For high school and adult, I like
this used in conjunction with the
Waldrons' nine volume series.
These are all curricula that take you through the Bible at an age-appropriate level/pace. I also have topical studies planned, but I'm pulling them from various other sources (some written by friends, some I'll create, etc.). We'll be doing an evidential history of the Bible (editions, printings, contridictions with other texts, proofs of authenticity, etc.), a financial stewardship course, a godly men course, a
geography/history course, etc. But those will be late middle school through high school. We're working through the R&S books right now... finishing #6.