If you used a facility in Photoshop to save your page as HTML then I think you might expect some problems. Photoshop doesn't really build web sites and when it is asked to try, it doesn't do a very good job.
There are lots of resources available to you but fundamentally you will benefit from some understanding of HTML and CSS if you want Dreamweaver to work for you.
Having said that, it might be helpful to see you live page.
I second martcol's reply. Photoshop is purely a design tool and it does very little when you want to export to web.
The methodology you've followed - Designing in Photoshop, Slicing it and exporting it as HTML is usually always considered bad practice.
You need to export what is needed from Photoshop, then let Dreamweaver take over - with the power of CSS.
This tutorial will help you - http://net.tutsplus.com/articles/news/how-to-convert-a-psd-to-xhtml/