Right here. First link on a google search for Lord of the Rings Online. You could have found that yourself.
I've played for a few hours so far, and it's pretty fun. Disappointingly, it seems not to give a shit about actually feeling like Lord of the Rings, introduces a bunch of new characters and cities that Tolkien never wrote, etc. Still, for those who either don't know or don't care that much about accurate lore, it's a pretty good MMO. Especially since Friday, when they made it free.