Activity
Dartmouth College

Dartmouth College: An Introduction to Probability

For Students 9th - 10th Standards
This site provides an introduction to probability book that is available for download. It also gives tips on how to teach and learn the concept of probability.
Handout
Khan Academy

Khan Academy: Probability: The Basics

For Students 6th - 7th Standards
Provides an introduction to probability. Includes examples, two videos, and links to additional resources, e.g., exercises to try. There are also problems and discussions of them in the Comments section.
Activity
Yale University

Yale New Haven Teachers Institute: Introduction to Mathematical Probability

For Students 9th - 10th Standards
This site gives an overview of probability, including example problems and a reading list. Exhaustive and detailed, this should help dramatically with students looking to study probability.
Lesson Plan
Shodor Education Foundation

Shodor Interactivate: Lesson: Ideas That Lead to Probability

For Teachers 9th - 10th Standards
This lesson plan sets the ground work for an introduction to and then exploring the concepts that are the foundation for probability. Lots of resources are available for teachers and young scholars at this website.
Activity
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math; Introduction to Probability

For Students 9th - 10th Standards
A good introduction to concepts in probability, this page also gives a great definition of sample space. Scroll down halfway to find sample space.
Handout
Estrella Mountain Community College

Estrella Mountian College: Introduction to Genetics

For Students 9th - 10th
This site explains genetic beliefs before and after Mendel, and also includes a section on Mendel himself and his experiments, entitled, "The Monk and his Peas".
Handout
Yale University

An Introduction to Mathematical Probability

For Students 9th - 10th Standards
This site gives a very brief definition of independent events. It provides a few example problems for further understanding.
Lesson Plan
Shodor Education Foundation

Shodor Interactivate: Lesson: Probability and Geometry

For Teachers 6th - 8th Standards
The Shodor Education Foundation provides this lesson plan to give middle schoolers an opportunity to connect probabilty and geometry. Students learn how to calculate probability, use geometry to solve probabilty problems, and, as an...