Many tutorials are available all over the place online. Check the Macromedia site for starters.
As for your navigation bar designed in Fireworks. If you want to do it that way, splice your image up in Fireworks, then export it HTML. (I primarily use Photoshop/ImageReady, but I'm pretty sure the process is simliar in Fireworks.)
You can then do one of two things:
1. Open the exported HTML page in Dreamweaver. Highlight the table and copy it into a new document, where you will design the rest of your site. (Make sure if you have any Javascript to copy it out of the header and into the new document).
OR
2. Just work around the exported page, inserting content above and below it.
There is an extremely good chance that this post made little sense. If that's the case, let me know and I'll try to explain better.