It looks pretty nice to me so far, however it looks a bit strange down the right side and bottom, as the page just cuts off.
The first big error you've made is that there's two copies of the doctype, head and body tags.
HTML Validator:
Line 78:
"Found an extra and/or out of place document type declaration (<!DOCTYPE ... >). Every HTML and XHTML document should have one and only one document type declaration, and it should normally be the first line of the document. An exception is for XML documents where the first line is normally the XML declaration (<?xml ... >) and the second line is the document type declaration."
Line 80:
"The "html" element cannot be used here. It is nested in another "html" tag and cannot be nested. Did you forget to close the previous "html" tag? This element may be contained in "(first tag)". This element may not be contained in "html"."
Line 103:
"The end tag for "span" was found, but "span" was never opened, has been ended too many times, or cannot have an end tag."
Line 122:
"The end tag for "br" was found, but "br" was never opened, has been ended too many times, or cannot have an end tag."
Also, try using normal text links for the navigation as they load faster, can be updated easier and improves Search Engine Optimization. You certainly don't need images for the navigation in your case.