@Paulie_D – Thank you so much for the assistance so far. I missed out the closing tag for the header div & I have corrected it now. I followed your suggestion and changed the link to the nivo slider stylesheet and the pictures appeared while previewing in browsers in dreamweaver. However, when I did it for the images (ie used the images were not found so I left it as it is).
I will move the css styles to a separate stylesheet & hope it makes a difference. Its just odd to me that when I preview the page in a browser in dreamweaver, I can at least see the pictures but once I put it in the backend of the website and check the address, the images and even the corporate logo (which has nothing to do with nivo slider) dont appear!!