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: 
IMHO, the best way to learn it is by doing it, make a plan for a website, and have a go at making it happen (repeat as required), by the time you put html, css, javascript, and eventually a server side framework together, it can be a bit of a dark art, and there is much learning that can only happen when you are actually doing it (and feeling the pain of IE 6). 

As mentioned by others, Sitepoint, Smashingmagazine, W3Schools (to name a few) are all handy references. 

Would also suggest learning jquery as you learn javascript, some good starting tutorials here <http://docs.jquery.com/Tutorials>.

Also install firebug in firefox so you can start digging under the hood of sites you like. 

With regard to books, from personal experience, I have a stack of outdated technology specific books that I have not touched for quite a few years. The ones that focus on why rather than how get much higher rotation.

If you have learnt java and c++, the mechanics of the technologies shouldn't be too hard to pick up, but many programmers tend to suck at things related to UI, so if you were to get a book, I would recommend "Don't Make Me Think" or other books related to usability and interface design.

HTH. Good Luck.
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.