do i need web design software to build website using mountain lion?

I'd like to develop a simple, yet nice looking web site. I do not know html but would like a way to build the site. I've seen software before like dreamwever but don't want the expense......and I think desing has come a long way since 2008. I have a new macbook air with mountain lion and would like some insight. I can't find iweb on the mac app store.