Hi Elaine,
We've recently converted from designing tables-based sites to complete CSS layouts because of the numerous benefits they offer.
One book which I could not recommend highly enough is "Cascading Style Sheets - Separating Content from Presentation" published by freindsofed. I must have referred to that book everyday for about 6 weeks, so it was well worth the 20 quid I spent on it.
Naturally, there are a couple of good websites that come in handy as well:
-
http://www.csszengarden.com/
-
http://www.mezzoblue.com/zengarden/resources/
-
http://www.glish.com/css/
Good luck with it.
Alastair