It doesn't matter if you do all the error checking in the world, or if you have the most beautiful graphics, if your site or application design isn't usable, it's not going to do well. Get input and advice on usability and user interface issues here.
I've bought the book Designing without tables from sitepoint.com. This is a book about designing your site with CSS, and I can recommend you this book.
thanks but i don't need any site anymore i found too many good resources on web but i need something to read at home and something written on paper
i will look at the book which jollyjumper mentioned.