A good place to go for things like this is diveintoamerica.com.
I hadn't thought of things like letting Internal Revenue know!!
As well as your Council (who, thanks to my horrible landlord, are still trying to charge me for a 'second home'
), cable/telephone, gas/electric, etc.
I also paid for a year of mail forwarding to my U.S. address and am emailing to get myself off of lists as unwanted catalogues etc. come in.
I was also billed after I'd given notice for my gas/electric, but after emailing them, they corrected it.