Hello,
I'm afraid this reply is a bit long, but bear with me :-)
Our six-year-old had been going three days a week to a private nursery, which he enjoyed a lot, from the age of three (and our four-year-old is there now). It's a pretty average but happy and mixed nursery, with little in the way of 'teaching' - they do a bit of letter formation and counting, but mostly drawing, painting, singing, dancing, dressing up and charging round the garden.
The local school is a CofE infant and junior school in a 'leafy' part of London (we're in the scruffy end of the parish :-)) with good reports from parents, Ofsted etc. Our son went there in the term before he was five and almost straight away there were 'problems'. He's a bright, active, interested lad and was bemused that most of the time at school was spent sitting down, not talking or moving, and being made to write out the letter 'A' thirty times, and so on. He's also the sort of lad who questions why he has to do certain things, and his teacher was pretty poor at explaining - rules were rules and were there to be obeyed, full stop.
Of course, a school needs order and discipline, but only because it can't function any other way. This 'control' aspect seemed to me to be more important than any other part of a teacher's job - apart from delivering the National Curriculum in an incredibly inflexible way. The idea that every child who is five can and will be able to read and write flies in the face of all our experience as parents. Children do all sorts of things at different rates and different times - and are usually best at creativity and learning when they're free to 'choose their moment' as it were.
As is the way these days, lots of stuff that I remember doing in the playground was banned - physical contact games, running and generally yelling - so our son would come home from school and need an hour or two running around, playing football or whatever, just to satisfy his need to be physically active.
It was becoming clear to us as his parents that his frustrations - and those of the school, which seemed incapable of accepting anything other than quiet, compliant little children - were not going to go away while he was at school, so we decided to take him out of school at the end of the summer term. To give you some indication of his teacher's attitude, she told my partner that 'children should learn to be bored' - after we had queried her decision to punish our son for fidgeting and talking by making him stand facing a wall for twenty minutes (which is not necessarily cruel - just an amazingly stupid way of dealing with a 'bored' child).
We 'de-registered' him from school - all you need to do is inform the headteacher of your decision, and you don't need his/her permission or that of the LEA. The only legal obligation on the LEA after that is to satisfy themselves that the child is receiving a 'full-time education' (whatever that is) suitable to his/her age, aptitude and abilities. It's a very woolly bit of law - some LEAs demand to see evidence such as written work on a regular basis, whereas others might just make do with an informal chat with the parents. Our LEA, in fact, hasn't contacted us at all since our son was de-registered last September. Most LEAs should offer a sympathetic ear (but no financial support) to home educating parents, but many in fact don't even let parents know that home educating is legal. If your child is younger than five, there's no obligation to tell the LEA at all that you are going to home educate.
You asked about SATs - which are usually presented as testing the children, but are in fact there to test the school. Typically, worried parents see them as essential hurdles for their children to jump over, for fear of 'falling behind'. Personally, I'm saddened by the often hysterical way that children are pushed, forced, coached and coerced into achieving all sorts of things that are in reality quite meaningless - I'd suggest that any happy child who is given support and encouragement but little or no formal teaching will be perfectly able to read, write, do arithmetic and know and care about tons of stuff to do with the world by the time they're, say, ten. Exactly when they do these things is quite beside the point, in my opinion. And the school our son went to was more, not less, likely to act against this natural curiosity and desire to learn than it was to support it.
I'd better leave it there for now, but I'll post later about what home educators often call the 'dreaded S word' - socialisation. But if you've any queries about any of the above, please let me know.
Best wishes