Another good free one is
Aptana. I am learning to build sites from scratch, and have found this to be a great tool. It was highly recommended from the writer of HTML, XHTML, and CSS for Dummies. The CD that came with the book had the program on it, but you can download it for free also. He also gave a review of Kompozer, but said this one is the one that he prefered, so I tried it since it was on the CD and I didn't have to download it.
I just currently finished my second website using Aptana and all is well. I have created html and css with it. I have also been able to edit php, so I am happy.