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.
CK-12 Foundation
Ck 12: Earth Science: Tides Study Guide
[Free Registration/Login may be required to access all resource tools.] This study guide summarizes key points about the different types of tides and the Moon's effect on Earth's tides. Includes a few questions to check for understanding.
Other
Bad Astronomy/phil Plait: Tides and Why Our Days Are Getting Longer
Why does the Moon always shows the same face to the Earth? Why is the Moon's rotation period the same as the length of time it takes to orbit the Earth? Why are there two tides a day? These questions and more are answered here.
Khan Academy
Khan Academy: Codex Leicester: Fossils/mountains, Moon/tides
An excerpt from Leonardo da Vinci's Codex Leicester. Find out how this "Renaissance man" observed the Earth and learned more about tides, moons, and fossils in the mountains.