Wow... where to start?
The first question is does your local government allow you to homeschool your children? In the US, this varies state to state. I don't know what the situation is in the UK and other countries.
Gonz, the legal situation in Indiana is described at the following link:
http://www.hslda.org/laws/analysis/IN.asp
The
Home School Legal Defense Association has information about homeschooling laws in every state of the US. It also has links to information about homeschooling in general: how to get started, curriculum, etc.
Once you know whether you're allowed to homeschool, then you can think how to go about it. The single source that helped me more than anything else was a book written by two women, Jessie Wise and Susan Wise-Bauer. The book is
The Well-Trained Mind: A Guide to Classical Education at Home. It outlines a course of study, beginning with pre-school age children and going through twelfth grade. It's a blueprint for how to organize yourself, and how to think about what exactly you're trying to impart to the child. It also has suggestions for textbooks and reading materials for each grade and every subject. I highly recommend it.
The "classical" part of the classical education is that the curriculum is organized around the idea of the trivium. Way back in the old days, the three primary subjects of a basic education were grammar, logic and rhetoric. Those three subjects were known as the trivium. You learned the nuts and bolts of language, then you learned how to organize your thoughts logically, then you learned how to express your thoughts coherently. The authors take this same basic outline, but they apply it by analogy to all subjects of the curriculum. Each stage lasts for four years. Each covers the same basic material (except math), but covers it each time in greater depth.
For example, in the grammar stage of history you learn the basic facts of history: names, dates, events. You go through history in chronological order, covering a particular period each of the four years. In the logic stage, you come to understand the connections between events. You go back over the same periods of history each of those four years, but this time with an eye towards logical organization and causality. In the rhetoric stage, you repeat the study of history again, this time focusing on forming your own opinions about events, writing research papers, etc. By the time you've gone through the history like this three times, you should have a firm understanding it.
The problem of how to bring an older child into this program of instruction is addressed in the book. I can't recall what they say about it, though. I would recommend the book even if you weren't going to follow the exact program, though, just for the lists of textbooks, reading material, and general tips that they offer.
If anyone's interested, I can provide a list of the books and materials that we've used so far...
One note about homeschooling sources and organizations: most of them have a religious bent. If you're an atheist, like myself, you will occasionally come across things that make you go 'eh'. Even so, you can find something of worth in what they have to say. The HSLDA has a religious component, but they're defending the legal rights of homeschoolers. The book I lauded above was written by two Christians. It contains a chapter on religion in homeschooling, and some of the materials it recommends have a religious bent. The authors are very good about pointing out which ones are more religious, and they don't push religion except in the one chapter where it's clearly labeled as such. (It's like, "and we now pause for denomination identification.")
So the lesson is, look before you run screaming. Glean what you can from wherever you can.
They were getting into arguments every time they got together, but I figured that was all part of the socialization.