I started learning XML now is the "no nonsense XML" of Taiwan's "two tigers". The name is cool, ah? It is not a language article, and the technical article written can also be so easy to understand, and you can get it free online, it is open, for free!
http://www.2tigers.net/
I like this spirit! ! !
But there is a little deficiency, maybe two tigers are too busy now, and the website has not updated more than a year. But it is my biggest gain from NoverBosexml.