Hi Maria,
All the Disney resorts provide transportation to the parks. All Star Sports will have a bus stop with many buses stopping throughout the day; at the front of each bus a screen will indicate the bus' destination, such as the Magic Kingdom, Animal Kingdom, Epcot, and Disney's Hollywood Studios.
To return to your resort, you will need to walk back to the bus stop you were let off at. But no fear if you forget - a sign is posted at each park bus area which lists the resort stops.
Now getting from resort to resort is a bit trickier since no buses run those routes. However, you can use any of the parks as a transportation hub. For example, I'd take the bus to the Magic Kingdom and then hop on the resort monorail to get to the Contemporary and Polynesian. The monorail is a fun form of transportation, too, that your sons may enjoy.