umm, I used the following 2 sites to help me last year when I was doing just what you're doing now...and it totally helped.
CSS Tutorial for reference
and
css Zen Garden: The Beauty in CSS Design for design and layout methods
also "a list apart" is a good site...
A List Apart: A List Apart a lot of good helpful articles on here...
as for your question about using photoshop still...
yes you can use photoshop to create your graphics and layout...but when you slice...just export the images, you don't need to export the html anymore.
(someone else correct me if i'm wrong)
Basically you will use xml for your layout (which is pretty much a stripped down version of html), then use the css to position and style it.
I hope this helps and if anyone knows better, just correct me :s