Best way to learn XML

[Zompton]

One day i plan to go to school to learn computer programing, and then specialize in video games. I cant start school yet because i am still in the Army, but would like to get a head start. I like making websites and would like to make mods for games like everquest. Would XML be a good programing language to try and learn? Where can i find a good book or prefferable program to learn XML?

I am considering taking an online course but first I want to check into XML and learn a bit before i start one. If XML is not a good place for me, what would you suggest?