This should give you most of the information that you need...
http://www.companieshouse.gov.uk/about/guidanc e.shtml
There is a phoneline for guidance and all the forms you need can be downloaded online. Many documents can also be filed online too.
You will need a company secretary, this is can also be done by an accountant or solicitor who can also maintain your company books. It is always wise to make sure you are aware of the obligations of company officers ie directors and secretaries, there is a booklet on the above link.
Many law firms have shelf companies which they can do a change of name job on. Usually they will have a standard memo and arts so if you want something specific then you may need to make some changes.
There are also a number of companies who can set up companies for you, from simple ones to more complex ones.
I have a questionnaire of the information you would need from when i have set companies up for people before, mainly property management companies if that would be useful, it's stored on my work directory though so I couldn't access it til Monday.
If you have a company name in mind then you can search here to see if it's already been taken. The helpline can also give you some guidance as to whether a name will be accepted too.
http://wck2.companieshouse.gov.uk/099967f65c5e c69a4ae7ef60b3c546fa/wcframe?name=accessCompan yInfo
There is also some very useful info in a booklet accessed off the first link.
York Place are pricier than some but can provide a great service...
http://www.yorkp