You can feel free to skip this entire article if you have a website that you are happy with... hold on, there's something else... and you can easily update it. Notice that I said you, not your latte drinking, jargon spouting, charge by the hour web air quotes consultant.
One of the main reasons to use a content management system is to enable you to update the content, and sometimes the look of your site. A CMS (I'll explain what it is soon) should enable you to do this in a painless way. In other words, without cracking open any sort of O'Reilly book with "the Definitive Guide" somewhere in the title.
This brings me back to what exactly is a Content Management System. Sorry, I didn't link you to this Wikipedia page because it's not all that helpful. In broad terms a CMS lets you have control of your website without having to understand all the code that makes it work. Of course there are many different CMSes, and some are better at this than others. But basically a CMS is like the controls on your car. The controls on your car let you drive a car without having to understand how an engine works. Now, some cars are better at doing this than others. If you've got a Fiat with 300,000 miles on it, then you don't get into the car without your tool box right? But if you've got a new Honda you may not even know where the lever to open the hood is. Basically, sometimes you're going to have to deal with the innards of your car or your web site, but hopefully not often.
Sounds good right? You don't want to drive a car and get oil on your hands, and you don't want to make a website and get ones and zeros on your hands.... or those < and > symbols or whatever. Now you just have to pick a CMS. I'll jump the gun here and tell you that Wordpress is often a good choice.
But you've got plenty of other choices, some free (as in beard (or leg hair), beer, or fall depending on what you pick): Concrete5, Drupal, Joomla, Wordpress... and some for payment (as in investment or hole in your computer screen you stuff money into that will be lost forever depending on what you pick): City Desk, Expression Engine, Sharepoint, Sitefinity...
I like Wordpress for small business sites. It's pretty easy to use, very flexible, open source, and built from PHP and MySQL which are also open source. Like I said, there's plenty of other choices, many of them excellent.
Ok, so where was I? Something about Fiats and oil on your hands. Time for Car Talk? Wait, I was talking about Content Management Systems and why they help you not to get your hands dirty.
So, a CMS puts the power back into the user's hands. Admittedly even a CMS has a learning curve, and sometimes you will run into things that you need to dive into the <!DOCTYPE... for. But this is why you have time and money. Oh you don't, well, what it comes down to is that you'll use less of both with a CMS.
A CMS handles these type of things for you. How? Well, by creating a bunch of control panels that let you add to, subtract from, and modify your site.
Don't worry even if you have a CMS, you'll still be able to throw plenty of money at your latte drinking, jargon spouting, charge by the hour web air quotes consultant... but you'll be able to do it while having control over your own site. In fact, the hope is that the more work you get done on tweaking your CMS to fit your needs, the more control you'll have, so all that money becomes a good investment, not just lattes down the drain.