When you have created all of the scenes for your comic strip, put them in the order you want them to be in the slide sorter window.  
To create a forward arrow on each slide:
> First, draw an arrow in the bottom right-hand corner of the screen.
> Next, click on the Selection tool and select the arrow. In the Behaviors window, click on the plus (+) sign.
> Choose <Screen > Go to Next Slide>.