well, the top-level div is set to:
<div id="container" style="left: 0px; top: 0px">
if you remove the style= attribute, then the browsers default margin settings will be used.
you could then change the <div id="navigation"> div to read:
<div id="navigation" style="left:0px;top:0px">
so that the menu is left aligned; same for the footer div.
I don't use dreamweaver or any other "design" software and create all my pages myself via CSS,HTML and PHP, so I don't know how you'd do this in Dreamweaver (short of manually editing the code); I'd imagine these settings are buried somewhere, though.