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...
Other
Physical geography.net: Introduction to the Hydrosphere: Ocean Tides
This is the last (18th) section of a textbook chapter on the hydrosphere. It explains what causes tides and tidal variations, describes some different types of tides, and shows on a world map where these tides occur. Includes link to a...
Other
Moon Tides: How the Moon Affects Ocean Tides
Discusses the different kinds of tides, high and low tides, lunar tide facts, questions people have asked about tides, and causes of tides.
Enchanted Learning
Enchanted Learning: Earth's Oceans Tides
This site explains what tides are and the difference between Proxigean Spring Tides, spring tides, and neap tides, and how these are formed. Graphic illustrations are provided.