How to make plugins for rhythmbox?

hi i would be very pleased if anyone might be able to either point me to the apropiate place, or would take me by hand for creating plugins for rythmbox.

plans for now are:

create a easy way to choose radio stations (from before created list)
import functionality of easytag into rhythmbox

and

make the genres to tags.

the last might not be done via plugin, but the first too might?

help appriciated.

thanks