I know a lot of teachers (including me!) that really love Edcite because all of the assignments are digital and automatically scored. This Edcite assignment gives students practice analyzing and evaluating historical documents. It could be used in an ELA or History classroom.
This is a fantastic place to go when you're ready to use primary sources in the classroom. There are graphic organizers, lessons, activities, videos, and a primary sources database -- pretty much everything you need in one spot!
PBS's History Detectives is a wonderful program that really grabs students' attention. This page gives detailed step-by-step instructions for teaching students how to analyze primary sources and distinguish them from secondary sources. I highly recommend it!
This project created by the Standford History Education Group is one of my favorite teaching resources, hands-down. It includes a nice list of primary sources for World and American History. What's even better is that it includes student-friendly versions of the primary source documents and complete lesson plans. Amazing!
This Edutopia blog post is great because it lists excellent places to find primary sources on the Internet and also explains each. It's a post to bookmark. There's even a section on iPad apps that are all about primary sources.