On the right sidebar there's a button where you can register (only takes a few seconds, doesn't even need an e-mail). After that you can post, or up/downvote questions you like or dislike.
just please learn reddiquette. the downvote button is not for what you disagree with, but rather that which does not add to the discussion.
Dislike. Of course, it implies it, so my fault. But, I didn't meant disagree with that.