Question: What's a good book, or a good way to learn HTML, XHTML, and CSS? I recently graduated from school and I only know Java, and C++.

I would like to learn some web development so I am looking for some good books and resources.

Answer: 
If you ask me, whatever introductory level book you can find at your public library on html or css or "web programming" is a great place to start as far as books go. Typically, those kinds of books are a little bit "stale" as far as you're likely to find something that's not the latest greatest version of HTML, but for the most part very few parts of the HTML spec get deprecated or removed from version to version, so anything you'd learn from slightly obsolete books will generally still exist, but 

There's a ton of great stuff online too about every specific topic you could want, for the most part, you could get by without buying any books
Here's a link (<http://jwinblad.com/webprogramming/webdesign.php>) to some of my personal bookmarks on web-development that I like to keep handy like the specifications for CSS and HTML that enumerate every possible tag or CSS property and give you a brief description of what each one means and is used for. 

Of course, actually trying out different tags and CSS experimentally is sometimes much more helpful in learning. If there's a website that does something cool, you can often times learn how to they do their cool feature by viewing the source-code of the page or its style sheet using the tools provided in your web-browser. Create a hello-world demo-page and then work from there on adding extra tags and a style sheet and so on. If there's something specific you want to do, you can search for tips on how to do that particular thing

If you already know Java and C++, it should not be difficult to learn HTML/XHTML and CSS. But if you're looking at learning this with the hopes of it being a career direction or paying job, you will probably want to delve into more than just HTML, nobody seems to be looking for people to write webpages that look like they came out of 1998 or 2001, you can get nicer looking stuff that that with almost no HTML knowledge using WYSIWYG tools...once you get the basics of HTML understood and know where to look up tags and CSS descriptors, you may want to branch out either into a client-side scripting language like Javascript or a server-side programming language or framework (PHP, Ruby on Rails, etc) or trendy web-technology like Flash. It kind of depends what your goals are in learning web-programming.
If you're looking for reference information, [W3 Schools](http://www.w3schools.com/) is a great place to start. [Smashing Magazine](http://www.smashingmagazine.com/) is great for pretty much everything to do with web development. I'd also recommend [A List Apart,](http://www.alistapart.com/) which often has great articles about some of the more difficult CSS concepts. And last, but certainly not least, I'd check out the articles on [24 ways](http://24ways.org); while they only have 24 updates every year (in December), they are written by some of the best people in the industry.

Ans since you're interested in web development, you'll probably end up wanting to learn some Javascript as well. ppk's site [quirksmode.org](http://www.quirksmode.org) is a great place for that.

Well, I hope this can be some help to you, and wish you best of luck. Also, of course, you can always ask any question that you have here at Stack Overflow.