Teachers TV is a UK television channel that is essential viewing for all teachers to understand school issues. I find it particularly helpful for my teachers as they like to see inside schools to see what the teaching is really like.
You can watch all their programs online, and they tend to be 15 to 30 minutes in length.
Here's a show about Girls Bullying that I just watched. I actually taught in one of the schools that they filmed in, which was quite cool for me to see.
If you want to know more about teaching in the UK, or in London in particular then you should watch one of these shows every day. That's the best way to prepare yourself. You can search for specific issues (behaviour management, secondary school teaching, curriculum advice, assessment, report cards, supply teaching...).
Reading helps of course, so go through this little blog. We have heaps of information on here!
Also, sign up for our newsletters and buy your copy of the Guide to Teaching in London: A Survival Guide for Canadians (the American edition is coming soon).