Like any skill, it is practice that makes you proficient.
http://www.slicingguide.com/ This tutorial uses a table-based layout. If you use Firework's HTML export mode, you'll get a table-based layout, so it might be worthwhile going through this tutorial. Even so, the author has some useful points about approaching the layout, regardless of whether it's implemented in tables or CSS. (When he mentions that using FW for slicing produces areas that break when the content changes, he means that the FW table-based layout is not flexible. FW produces an exact copy of your design. Messy code, but it reproduces your design. When you hand-code a table-based layout, however, you can design for the areas that need to be fixed in size and the areas that need to be flexible.)
http://www.apoorvvaidya.com/creating-a-website-from-start-to-finish-part-1 A three-part video tutorial. I haven't watched it, so I can't comment on it, but the blog comments are favorable.
http://net.tutsplus.com/tutorials/html-css-techniques/design-and-code-your-first-website-i n-easy-to-understand-steps/ This is a CSS layout tutorial.
None of these tutorials is specific to Fireworks. As long as you understand how to create slices and export images, though, you should be able to follow along with any of them.
This tutorial may be something you need to follow:
TAKING FIREWORKS COMP TO DREAMWEAVER:
Personal opinion: Never use the html generated by a graphics program :-)
Slice your comp, save the images and BUILD the page in Dreamweaver. The above tutorial will teach you how to do that.
Further tutorials that may be of benefit:
From Tables to CSS Web Design Part 1 -
From Tables to CSS Web Design Part 2 -