Actually, I think there is a better plan then the one I suggested above:
Right when you get off the Ferry, turn right on the boardwalk (in front of the Island Market).
You can follow the boardwalk down to Marine Ave, turn left onto Marine. Stay on the left side of the street and walk along the shops until you get to the end of Marine Ave at the bridge.
Then cross the street, and walk back the way you came, to see the shops on the other side of the street. By the time you get to Park Ave, you will have seen all the shops (at Hershey's Market). Take a left on the sidewalk there, and you will see the bridge to Little Island ahead of you. At the base of the bridge, you will see another boardwalk, turn left and it will take you along the picturesque Grand Canal.
Follow the boardwalk along the Grand Canal, and it will wrap to your left, and then follow the boardwalk past the Marine Ave bridge, along the North Bayfront, and the boardwalk will wrap around the western tip of the Island, past the bridge to Collins Island, along South Bayfront, and you will be back at the Ferry dock.
This way you get to see all of the shops, both the North and South Bayfronts, and the Grand Canal, and don't have to do any backtracking.
Edited: 17 May 2012, 18:18