Like the post above me said there are many great programs for designing a website. Many of those programs in the list are great.
NVU is another free alternative to Dreamweaver, but I don't like how it formats some of its HTML code. Besides that it's an incredibly powerful WYSIWYG editor that is on par to Dreamweaver.
Notepad++ is my favorite text editor, it can color code HTML, CSS, PHP and many other non-web programming languages. I'd only recommend using a text editor if you know HTML already.