Safe to Sell?

I searched the forums but couldn’t find an answer for this specific question.

Do you need to file for a copyright before selling your original Flash game on CD? And/or the name or logo of the game? Or your personal logo? As much info as you have will be appreciated.

The thing is very nearly ready and before putting a preview online it’d be nice to know if I’m going about things legally and protecting myself too.

Thanks.