What are the best websites that provide free training in programming languages?

www.w3schools.com/ best place for beginners then you must chose what you want to be expert on it like php, asp.net , or maybe ruby im php specialist you can try YII framework www.yiiframework.com/tutorials/

for basic learn, it's w3schools.com.
if you want more advanced you need to learn by video tutorials.
here you have a link http://net.tutsplus.com/

For French speakers, you can try http://www.siteduzero.com It is really helpful with good explanations (many technologies and programming languages)

http://net.tutsplus.com Nettuts+: Web development tutorials, from beginner to advanced

I would not recommend w3schools site since it contains a lot of misinformation, see here http://w3fools.com/ I'd suggest more reputable site such as: http://www.codecademy.com/ http://www.codeschool.com/ http://teamtreehouse.com/ Some of those site charge money for some of their premium content (much like http://net.tutsplus.com) but a lot of it is free.
Cheers!

http://www.w3schools.com/

For absolute beginners, HTML, CSS, PHP: [http://www.w3schools.com/] is good and interactive Javascript, Ruby on rails: [http://www.codeacademy.com/] is a great website, full of interactive and useful problems...
PHP frameworks (if you already know PHP): Yii framework has one of the best and easiest tutorials and reference guides available online [http://www.yiiframework.com/tutorials/] For Pros: I really recommend reading the references and standards along the execution of any real project, invent one!

www.thenewboston.com.
They are the best for now!

W3schools is very useful but their information is very basic and sometimes they tend to omit critical details.
For advanced HTML and CSS: http://www.htmldog.com/ For advanced PHP and MySQL: http://www.tizag.com/

onlinegooglevideos and youtube 

https://code.visualstudio.com