BBC
Bbc News: Focus on the Slave Trade
BBC News offers a short summary of the slave trade from Africa to the Americas. Gives statistics on the number of slaves (estimated at 10 to 28 million), where they went, and the cruel conditions of their enslavement.
PBS
Pbs: Confronting the Legacy of the African Slave Trade
PBS offers an excellent site with the description of some of the areas that supplied slaves.
University of Wisconsin
Uwec: West African Slave Trade Map
A map showing the numbers and routes used in the slave trade.