To be honest if it's a business website you can ill afford to spend the time learning how to do it yourself. This is no slur on your abilities but the unpleasent truth that learning curve is pretty steep for a novice.
If its an old site that's had nothing done to it for two-three years put some feelers out for a local web designer and ask about having them do a WordPress site for you, you'll be much happier with the end result long term.
Alternatively create a new website yourself using WordPress,
it's a lot like the ads you see on the telly but has more features.
Bespoke site alterating/creation
There are lots of good tutorial sites such as Tizag.com, HTMLdog and W3Schools that cover the rock bottom basics.
Free editing tools for the code and graphics are also available with varing levels of complexity, again Google is your friend.
BUT do avoid anything that says WYSIWYG what you see is what you get one of the common headaches faced by website designers is that web browsers such as Internet Explorer, firefox, opera and Chrome all display web pages slightly differently, screen size is another issue. So what looks fine to you may be an unholy mess when viewed on another PC.
If you need to pick the brains of a Web Designer in the UK you can find them over on this forum http://thewebdesignforum.co.uk/
Lovelogic.net UK Jobs Scanner
