Ok, you asked for it

. First thing, if you're going to use CSS and proper markup, be it HTML or XHTML, put in a DOCTYPE. You're closing your tags properly, now put in the XHTML doctype to go with it. Make sure you close ALL tags, including the <img> tags if you go with XHTML.
The image as a header is fine, it's just a bit too wide. Even at 1024x768, my horizontal scrollbar comes up and you don't want that. Better to either move it left or narrow it down to no more than 780 wide and center it.
Your menu - too small and not prominent enough.
Don't use text and <br>'s for a menu, if you're going to use CSS, use a list for menus like this. You can have rollovers and backgrounds and make some very nice menus with CSS.
Don't use paragraphs and breaks for headings. That's what the H1-H6 tags are for. Use padding and margins to space out your text, not <br>s.
Now for your CSS.
It is not necessary to absolutely position everything. Use the natural document flow and source order. You're better off using floats, relative positioning and correct use of margins to position your elements.
For font sizing, use em's or percentages. 1em=16px and 100% = 16px. If you lock your font sizes with px or pt sizing, you prevent people using IE from being able to re-size your text. What you've got is a bit too small, but if you want it small, leave users the option to resize for readability. Not every visitor is 15 with 20-20 vision.
Scrap the 1000px on your containers. If you want them to stretch use 100% for width. In IE's broken box model, the total width is the box size PLUS padding PLUS margins, so keep that in mind.
Rethink the absolute positioning, you'll thank me for it in the end. Absolute positioning takes that box OUT of the normal document flow, usually NOT what you want. I would suggest making your container position: relative, float the left column left, push the center content area over (no float) with margin, then float the rightside box with float:right. If you use floats, you must learn to clear those floats to prevent float drop and other funky behaviors.
That should keep you busy for a while

Glad to see you want to do it with CSS.