Weathering - Geography4Kids explains the different types of weathering.  Did you know there was more than one kind?
Erosion - Geography4Kids explains erosion, too.
Weathering and Erosion - This is a cool site from Study Jam, but you will need flash to watch it.
Weathering and Erosion - National Geographic can definitely help explain the processes that help shape our world.
Weathering and Erosion - This one is from Geology for Kids.