Has there been any information about more One-Punch Man episodes being released? I've finished the 12 One Punch Man episodes and the OVA.

As far as I know there aren't any more episodes. Is there any news from a confirmed source about a second season coming?
No, there has been no official announcement as to a second season right now. But the manga artist however did tweet the following

Which does seem to hint to working hard on the second season, of the anime
One punch man was a great hit and got pretty good sales figures, in both manga, anime and figurine sales. So the second season is almost set in stone, but until the actual announcement is made, don't expect to much!