It sounds like you need to go back in Dreamweaver and reconfigure your site (Site > Edit Site).
Unless you're running a PHP/MySQL site and you've installed those on your own local computer, it should be pretty straight foreward.
Specify the Name of your Site. -> Select "No, I do not want to use a server technology." -> "Edit local copies on my machine, then upload when ready." -> Specify where you are saving your local files. -> Specify how you want to connect to your server. (I use Filezilla for most of them).
When you create your site, you need to make sure that all file and image placements locations are relative to the site root rather than the document. That way you don't need to worry about any differences between your home computer and your Dreamhost server. As long as you transer all your images and files into the folder with your domain name on it in your account you should be fine.
As for previewing, as long as you've got everything set up like this, you should be able to go to File > Preview in Browser (or F12).