[font="Calibri,Arial"]You will need:
HTML for the actual page.
CSS for the layout
and if your doing anything complicated:
I wouldn't use Dreamweaver as such tools are the mark of a poor developer and can often generate piles of unessecary code. Also it costs €300 while HTML and CSS are free to use (Notepad, Wordpad, Notepad++, any text editor will do).
For the sake of your own sanity, do not use tables and 1 pixel spacer GIFs to lay out your page. This is how we did it in the 90's . Now we have CSS. Put your document structure only in the (x)html and then use CSS to do the formatting and layout. This way has many advantages.
The first question to start any project is not "how do I use this tool" (html, css etc) but what tools do I need to do this. To answer that you need to know what the site will be doing. Is this website just some information about the business, or is it something more dynamic? Does he sell things, and will he want to start doing that online?
Realistically if this is for a business and you don't know what you are doing you should not make him a site. A bad looking website will hurt a less established business more than it helps, because it projects a bad image. It is the difference between a commercial and an infomercial. No one will trust someone with money if they go to a site and they look to inept to even get a simple website made. This is assuming the business isn't already well known and liked locally, then people will just ask why your site is so bad.
I agree that dreamweaver can generate a bunch of junk code... but if you know html/css it is a lot easier to create an awesome page and tweak out the junk code. I myself use photoshop to create my pages (along with illustrator), then when I create my page I splice it up into what I want, transfer it over to dreamweaver. Then from there I clean up the coding. (Which is necessary most of time).