Ducksters
Ducksters: Earth Science for Kids: Ocean Tides
Did you know the rising and falling of the sea level is caused by the gravity of the Moon and the Sun? Kids learn about ocean tides including tidal currents and types of tides on this site.
Woods Hole Oceanographic Institution
Whoi: What Causes Tides?
The Woods Hole Oceanographic Institute provides an in-depth but easy to read article on the role of the moon and the sun in respect to tides.
NOAA
Noaa: National Ocean Service: Education: Tides and Water Levels
A great resource for explaining and understanding tides. Find out what tides are and why it is so important to monitor them. This is an extensive tutorial followed by a set of review questions. All of the information can be downloaded as...