Css+xhtml - having difficulties..

you use divs to layout the page

see w3schools.com for a good example

You don't use tables at all. it is like boxes inside of boxes, in this
example the container here is the main div which hold every other div:

container
A- Header
- Logo
- Navigation
B- Contents
C- Footer
----------------------------------------

<!--#container -->
<div id="container">


<!--#header -->
<div id="header">
<div id="logo"> your logo goes here </div>

<div id="navigation"> your navigation goes here </div>

</div>
<!-- end #header -->


<!--#contents -->
<div id="contents">your contents goes here </div>
<!-- end #contents -->


<!--#footer -->
<div id="footer"> your footer goes here </div>
<!-- end #footer -->

</div>
<!-- end #container -->

----------------------------------

I think you should consider downloading a free tabless layout and try to figure out how everything is working. Keep in mind try to find a very simple layout so you can learn, as the more divs you have the harder it gets.

Try
smashingmagazine.com/2007/01/12/free-css-layouts-and-templates/

Also like the above post said w3schools.com is great place to start.

Good luck.

you can design with tables and css, but it is usually better (and possible) to use only css. given your questions, i would say that you've done very little reading on the material and the basics aren't hard to learn - especially for a prodigy