Go in the Div direction if you learn to use a CMS like Wordpress or Drupal, it will introduce you to layups with Divs and Spans much easier to control. Also much deeper understanding of CSS helps with layups using Divs etc
There are loads of guys on here who can show you much better than me but its a start
Take a look at the box model, that will give you some great direction on how places div's inside divs, this is how websites are now structured following certain guidelines. Depending on what layout you are looking for would also depend upon what framework to use.
Harry Roberts has some wicked resources over at his site, check it out at;