Hi Jon and welcome to the board.
To cover all areas relating to starting a new business would be a massive undertaking. But much of the info. you are looking for is available on this site. Just browse through the previous topics or use the search facility.
Training is absolutely vital. I feel that generic based training is of more benefit than that of a manufacturers "Branded" approach. I feel that the NCCA (0116 271 9550) would be of greatest benefit to you. They run a 2 day course for carpet and upholstery cleaning in Leicester. IICRC also give superb training, but may be a little too intense and will require 4 days of your time and money to cover carpets and upholstery. Of the manufacturers, Prochem, Chemspec and Alltec have excellent reputations. There are obviouisly others too, but I have no personal experience of their courses.
Before you start, ask around other business people in your area about accountants. Don't necessarily accept the first one you see, but find out what they can do for you, speed of service, whether they charge you for every single call/letter or just offer you an overall package within the price. V.A.T. isn't compulsory if your turnover from all business activities combined is expected to be less than £55k (?) pa. This would be an enourmous turnover for a fledgling one man carpet cleaning business marketing himself to the residential market. Discuss this with your accountant.
If you are mechanically minded, you may wish to consider second hand equipment. The working components are generally considered to be consumable items. If you intend to buy new, yes research the marketplace, but it may be wise to choose kit from a local supplier. It can save a lot of time, cost and bother.
To get a feel for our industry, why not approach local cleaners and see if they are prepared to give you a taster for what it's about? Quite a few of us on Cleanitup have done this.
Finally, this Wednesday pm, we are holding a branch meeting of the NCCA just off the M1 near Nottingham. Non members are welcome. It's a 5.30pm start. If you're interested call the NCCA at the number above.
Safe and happy cleaning:)
Ken