I'd advise using a pre-built CMS (Content Management System). There are tons available, some even for free. Below is a short list:
- DotNetNuke (my recommendation as I've used it quite extensively)
- Sharepoint (massive cost, but great support since it's a MS business-class product)
- Wordpress (best for blogs)
- Drupal (best for blogs)
- Joomla (OK for anything, but DNN does it better I think)
- Many, many more!
Setting up a website for someone with DNN is as simple as deploying it on the server (if using a Windows Server, you can use the Web Installer and it will do EVERYTHING for you), walk through the install wizard, find a skin you like (free or paid, there are tons of sites that sell them), and fill in content!
I currently have 6 websites, 2 intranet sites, and 1 blogging site all running under DNN. I also have 2 sites, with a couple sub-sites each, running on a Sharepoint server.
Let me know if you have any more questions!