I use Dreamweaver when I need to do something really complicated. I don't really reccomend this, since it is expensive.
In the past I used TextPad (
http://www.textpad.com/) when I was learning to write HTML by hand. It is like Notepad, but it has a long list on the left side with standard HTML codes which you can just click to enter into the document. Saves a ton of time.
Finally, I used postnuke, as reccomended above, for my old website. It is powerful enough once you get a good theme going that your website will look really professional. You can spend more time with the look of the site, making it unique, than worrying about coding and keeping the pages organized.