I am a sole trader running my own PC Repairs Business.
I contacted the Princes' Trust and got accepted after writing a truly wonderful and extensive business plan. I was then given a grant of £950 (Postcode Catchment) even though where I live is in a really nice Greenbelt area (so worth a try) and I'm also paying back a loan for £2000 with 3 percent fixed interest for the duration of the loan - that's some loan...
So I basically got my financial prerequisites sorted from the outset.
I would thoroughly recommend you go to the Princes' Trust. To be totally honest though, I only did it for the money, the business mentor help is a neccessity and kinda annoying but in year one you only have to see him her once a month for half an hour... currently I'm in year 2 where it's once a quarter and I don't really mind now...
It's just for me I don't need any mentoring
Business Link's website is very helpful and resourceful, helps you to understand the taxes, NIC's and returns etc. you'll need to do..
Once you're started keep records of EVERYTHING (expenses like petrol, hardware for customers etc.)
You'll also need to keep a record of invoices and a cashbook of ingoings and outgoings.
Set up a business bank account to keep your finances easier to manage.
Never refuse a cup of tea (your customer might think you don't trust them, which won't be nice now will it?

)
I just carry a metal briefcase around with me with my business cards, screwdrivers, CDs with various and uber elite comp software you've probably never heard of before!
There are also other things like SATA to USB Laptop HDD Converters and such which come in handy...
Memory sticks are a God send as everyone these days has USB ports. Carry a spare router with you, and get yourself a work's laptop for testing purposes, such as Internet Connection problems etc.
Things I did were Business Plan, Business Card, Flyers, Adverts in local Magazines... send the flyers to the places the mags cover and it will really make an impact...
I also got magnetic signs for my car with my business logo on. Great because when you go on hols etc. and don't want people in the carparks you're going knowing that your vehicle *may* contain PC stuff u can take the magnets off.
Think I have covered everything
You WILL need a house phone number though
I never trust anyone who just advertises a mobile number as you can't trust them as easily as someone with a landline (fixed address)....
Can't really think of much else, if I do I'll write more...
Oh, and if it works - it's one of the best jobs you can do. Choosing your own hours is awesome. I could never work for anyone else anymore, and not having to report to a grumpy old boss - oh how I don't miss those days...
