Besides lesson plans on topics in Louisiana history, The Historic New Orleans Collection website includes the following additional online resources.
 

Primary Sources
Primary Source Database for Educators

Virtual Exhibitions
Voices Of Progress

Purchased Lives: New Orleans and the Domestic Slave Trade, 1808–1865
Selected readings
Lost Friends Database

To Be Sold: The American Slave Trade from Virginia to New Orleans
Symposium video

Williams Research Center
Quick WRC Guide for Educators

Timelines
Battle of New Orleans
Katrina + 10 
Henry Howard: Louisiana's Architect

Podcasts
Tripod: New Orleans at 300