Tutor2u
Tutor2u: Shifts in Market Demand
This is an easy to understand site that presents the law of demand, changes in quantity demanded, and the factors that cause a demand curve to shift. It also discusses how inferior goods and normal goods respond to changes in demand.
Khan Academy
Khan Academy: Changes in Equilibrium Price and Quantity: The Four Step Process
Analyze some step-by-step examples of shifting supply and demand curves. This resource is designed for students who are taking a college-level microeconomics course.