It can all seem very daunting moving back to the UK. This is the spot to share any useful info you've picked up along the way on schooling.
The department for school, children and families website no longer works, and it appears that you can find the information here: http://www.education.gov.uk/
3 Year Residency Rule
In order to obtain "Home Fee" tuition at a university a British Citizen returning from abroad has to have been resident in the UK or an EU country for three years prior to the start of their course. Also they may not be resident in the UK or EU wholly or mainly for the purposes of receiving full-time university education at the home rate during any part of the three-year period. It's something that you will need to consider if you are returning to the UK with teenagers who intend to go to university. The simple fact of being British does not qualify a student for the home tuition fee.