In case you missed it the Battlefield 3 open beta went public today, link to the site is below;

Battlefield 3 Beta Link

Basically to get going just means downloading and installing Origin, then when you’ve created an account and logged in, go to the free games section and you can get BF3 from there. The download is about 3.9Gb so it may take a little while depending on your connection.

Enjoy!!