Go here. Register on the site. Get a robot.
[Edited to add: Robots are now available.
It does look like your account needs to be tied to a Battle.net account. I plan to do that to mine tonight once I get home. On second reading.. I'm not entirely sure. My account isn't tied to battle.net.. and I was able to "redeem" the pet. So not sure if one will be in the mail when I get home or not.
I -think- fuel will be available tomorrow. I believe you can use the pet w/o the fuel.. but they will only battle if you have the fuel. ]