Yeah, look for a more attractive, subtle background. At least reduce the contrast on these stripes, but either a solid or a less strong image is in order. Check out
http://colourlovers.com/ for background images. You need to work on your box model. Padding + Border + Margins aren't set right. Example, the body text should have some space from the grey containing div.
BTW, dont use dreamweaver if you really want to be good at design. Make it in photoshop. Write the HTML, at first you should largely stick with known good templates, because interbrowser compatibility requires a lot of odd stuff. Then add in the CSS and cut up images from photoshop to get your end result.
Go step by step, don't try to learn it all at once. For example, take a PSD from a template site and try to make it into the html / css. Or make a PSD and ask for feedback if its good. After all, there really are two distinct phases of site creation, the creative impulse and the technical realization of the idea.