Ok, so we know kids are all over the board in terms of education. Nothing is universal and many children are finding school is lacking the challenge that makes students feel smart or successful.
In my recent investigation of whether or not to teach my son at home, I found a book that can be used as a curriculum guide OR just as a really good agenda of where kids should be if they want to get the maximum benefits from a classical education. It offers suggestions, tips, books, resources and examples of where children should be and what types of lessons they benefit from at which ages. I picked it up used and I read the first 75 pages the first night with pure interest. It's almost 700 pages in overall length so you can use it as a reference.
There are benchmarks that go along with ages and stages; and this book offers some really challenging but insightful direction for teaching to the benchmarks. Not to mention, it gives some well-needed confidence boosting to parents who feel they can't possibly teach this stuff at home!
The educational model is called the trivium, a renaissance-style learning where things are a) interdisciplinary and b) on a continuum. We talk about all this in teaching school but I rarely got examples of WHAT I should be combining and spiraling.
Anyway, the authors Jesse Wise and Susan-Wise Bauer start with preschool and continue plans through high school. It's not so much a teaching manual but an overall blueprint with tips and suggested curricula to meet the academic levels. It's certainly more "traditional" in content but it provides really great reasoning behind certain claims.
Even the most play-based parent will appreciate many points on literacy, reading and home-based learning ideas. Good luck and check out the book HERE. There is also a bunch of other stuff to check out on the site...good luck!