I would like to learn moders XHTML and CSS programming. Does someone has any good book suggestions where to start? I would like to have a book where I can learn those languages completely or as much as possible and I can use them if I get trouble on my web-programming projects. And of course I would like that my sites passes web-standards and validators and teaches what are different DTD's.
Don't waste your money on a book, there are so many good websites that do this:
All of these websites are free and will help you begin learning web development.
I have only ever needed Dynamic HTML: The Definitive Reference. Having a first edition from 1998 means everything it contains is supported almost eniterly in modern browsers. The 2nd edition is still pretty old from 2002 though so that's probably similar.
I also make good use of Peter-Paul Koch's excellent site quirksmode.org which covers browser compatability about as well as I could imagine anyone doing.
I suggest CSS: The Definitive Guide if you want to really understand how CSS works. There's some how-to, but more information on what the rules mean and how things work.
This is how I learned CSS, and it makes a great reference. From there you can understand more of the clever tricks you find online.
Head First HTML with CSS & xHTML would be a good starter book. I have not read it specifically, but have read others in the Head First series and think they're excellent.
They are specifically for beginners, and use a lot of innovative techniques for helping you understand and remember what you're learning.
Css Mastery - is the best CSS book I have read. If you think you know a lot about CSS, this book will open eyes!
I learned from the CSS Zen Garden and the associated book, The Zen of CSS Design. I'm not sure that's the best way since the books are more about the design aspects of css, but it worked for me.
I would second the recommendation of Head First HTML with CSS & xHTML.
Other good "starter" books would be:
All of the above are very readable and focused on the practical.