I don't think there is any webpart has been developed so far that will provide what you exactly want, however as you said you need advise for where to start then I would recommend you this.
Download SourceCode for this WebPart named as SharePoint 2013 Carousel WebPart with Nivo Slider and in class
public class Nivo : System.Web.UI.WebControls.WebParts.WebPart
/// Gets the slider items.
private List<SliderItem> GetSliderItems()
Instead of getting information like image, title from Image library, you can get data from Announcements list instead.
If I had SharePoint 2013 and Visual Studio 2012, I would had code it and test it but un-fortunately at this time I can't.