Hi there, my story is similar to yours, qualified in 2002, dabbled a bit then did nothing. I have like you decided that I want to follow this career path. I have the Guild insurance and find it really good because it covers me for mobile, home based work and salon work ( I currently work from home, but am in talks over renting a table a couple of days a week at a local hair salon).
The other obvious thing to point out is that you need to inform the lovely people Inland Revenue that you will be self employed, and they will send you a lovely form called a Self Assessment tax form (uuurrgggghhhhhh). Joking aside though, just make sure you have all your day to day requirements in place, such as files and lotions and potions, so long as you have that, then you can see what people want and expand the services that you offer to suit. For instance I do not carry a stock of polishes, but if I have requests for it, I will invest, but not until then because of the cost (maybe just a few key colours).
Lots of people use vistaprint.com for business cards and flyers etc, look them up, they are great value for money and give a very professional edge to your business. Most of all be patient though, it takes time for a business to develop so make sure you are getting as much local advertising as possible too. Use A boards outside the shop, and arrange for leaflets to be delivered in the local vicinity.
Just a few ideas to mull over..