I haven't moved into ASP.NET yet to play with master pages (soon I think...) but for the CSS vs. Table battle I'm totally in favor of CSS.

The Sitepoint book DHTML Utopia: Designing Without Tables Using CSS was a great resource for me. There is a Second Edition out now... haven't seen any of the changes in there though...

I'm a big fan of the Sitepoint books, they are pretty easy to read and give a good deal of information.