Dubai Stu's advice is great and there's not much I can really add! IT equipment is fine, kitchen and similar appliances can be more problematic, and you should buy a new landline phone handset when you get here.

As the number of Brits wandering off planes at LHR with newly-acquired IT equipment in their carry-on bags will testify, moving items from US to UK power supplies is usually straightforward. Computers and IT equipment generally is often significantly cheaper in the US, so stock up on things you need before moving over here! Changing the power cord is not a problem (these can be bought inthe US, and also in the UK - Maplin (mentioned above) have lots of UK stores plus a UK online store, and will have what you're looking for.