Before I left the army I went on a 2 day business start up workshop. Obviously you can't learn everything in 2 days but it was intense and there was some very good information available. Everything from marketing, customer service, business plans, financial managment etc. Some of it I already knew from my own research but it was aimed at forces personnel (most of which have had their arses wiped for them the last 22 years) so it was structured towards people who know very little.
With regards to pricing the guy said don't start too high as you will struggle to find any customers to establish yourself, start too low then you will, as other guys have mentioned in their posts, work all the hours god sends. Not only that but they will be very reluctant to stick with you when you do up your prices as they will look for someone who has the same low prices as you previously did. Not only that, some people will be scared to up their prices as they will be scared to lose any customers they have worked hard to to get. The longer you leave it the more difficult it will become and it'll reach the point where you are working so hard to make peanuts and see no way out.
The answer is to offer a fair price and do an excellent job, resolve any customer issues. Everyone makes mistakes but by dealing with them professionally and quickly you can still get good recommendations.
Although I attended a self employment workshop I am working for a company at the moment. Always keeping an eye on going it alone, the stress and hard work and pressure will be do me fine. Everyone is different, I work hard for my company and I enjoy it but I am building my experience and learning at someone else's risk. This is the same for any company they carry the risk of our mistakes.
Try and get price lists from companies in your area or even get them in to do some quotes in your own home for work to get an idea. Then ask yourself what you would do the work for. Obviously don't undercut them massively just compete with their prices and offer a good service.