Whether you get into the beta or not, you can get a feel for Hearthstone by checking out the two match videos they've released so far -- one showing Jaina battling Thrall and the other showing Garrosh battling Uther. But for now there's nothing to do but sign up and be patient until the beta gets started. Read on for instructions!
Step 1: Log on to your Battle.net account. If you don't trust our link -- and you should always be careful about clicking links that ask for your password -- just type us.battle.net into your browser bar and click the log in option along the top of the screen.
Step 2: Head to the beta management page. If you used the link above, you're already there! Otherwise, once you log in, you'll have to click Account in the top bar and Beta Profile Settings on the right-hand side of the screen.
To do this, you're asked to download an application (for Mac or Windows) that checks out your computer and populates your profile. Once you've downloaded the application, unzip it, run it, and follow the (simple) on-screen instructions.
While this doesn't guarantee you'll get in when the beta starts, signing up is your only way to have a chance. So good luck!