On the left side of the screen I have an area for weapons (bombs) in which there are piles of the different types of bombs. Each type of bomb has a limited supply (say 10). When the user is playing they drag a bomb on to the arena and let go, at which point there's a three second timer before the bomb explodes.
What I'm stuck with is how to implement this. I know that I'll need a table for each type of bomb, but what I can't seem to fathom is the event listener stuff. I know it's all fairly basic stuff but I just can't seem to get my head around it at the moment.
Any help at all would be very greatly appreciated.

Look at the DragMeMultitouch and Air Hockey 2 sample code to see how this is done. There were a couple of threads on this recently, so search the Forums for help.

-David