My advice...take a lot of deep breathes. Realize that things will not go as smoothly as you'd like. That even though things seem very similar, that there will be some VERY frustrating differences. Realize that there are many of us in London so if you feel the need to get together with a bunch of expats, we're not too far away. That in the long run, you will be OK!
Short run - don't let a mini-cab pick you up that you didn't order (these are different from black cabs & it's illegal for them to do so...plus sometimes dangerous)...some of them are great so if you need any suggestions for a mini-cab company let us know (they are less expensive). Buy an A-Z (pronounced Zed by the way) map of London - it will be INVALUABLE...get the one you can pop into a bag or carry easily. You will need it even after a few years here if you are planning on going anywhere new. Get an Oyster card as soon as you can - you get to ride the bus and tube at a much cheaper rate (it costs £3 for the card in the beginning but they'll replace them for free if they break or get lost) and they are so convenient...you can either use the 'pay as you go' option or get a travelcard on it. There are tons of internet cafes in London and they aren't super expensive. It's a great way to get in touch with home and here!
I'm sure there is a ton I could add but can't think of anything else quite yet. Best of luck! And truly, let us know if there is anything you need!
