A sabbatical in London - figuring out the expenses

My husband might go on a 6 month sabbatical at University College London this next year.

We are trying to figure out about how much it would cost us to live there for 6 months to see if this is even a possibility.  Our 3 daughters (16, 14, 11) will be with us, so we need 2 to 3 bedrooms.  We need to keep are rent down as low as possible without living in an area that would be bad for our girls. 

So many questions - and more that I don't even know to ask.  Council tax & utilities or bills included, commuting & whether it's worth having a car in the greater London area, other expenses I might not expect... In what areas/suburbs would it be better to focus our search for a rental and where should we absolutely avoid?  Any other tips/advice?  Perhaps this is too much for one post but I appreciate any help.  I'm sure you can tell we have not done this before. 

Thanks.