For the next two days, the Humble Store is giving away Lego: The Hobbit to everyone who signs up for the Humble Bundle newsletter.
It's easy. Go here, click "get the game." You'll scroll down the page a ways to a spot where you can enter your email address to subscribe—or, if you've already done that, where you'll see another button that says "get it now." Click it now!
OK, well done. And you're basically finished. A link to snag your free Lego: The Hobbit will be emailed to you, or you can use the "preview your email" button on the page that you should now be looking at. This is an optional click, but should you choose to click you will find yourself transported to a new page, facing a gang of angry minifigs and yet another button, this one labeled "download now." Another click, another scroll downward, click to reveal your Steam key, click to redeem it, click to continue, and finally—finally!—you are done. Lego: The Hobbit is yours!
It's actually not all that onerous a process, and you can't beat the price. You can miss it, however. The Lego: The Hobbit freebie offer is only available until 10 am PT/1 pm ET on December 15, and the Steam key must be redeemed before the same time on December 20.