Teach The Children Well is an extensive and excellent collection of links geared towards elementary students and also accessible to Intermediate English Language Learners.
It’s organized by Elaine Doolittle, and I learned about it while digging around the archives of Phyllis’ Favorites.
The links seem up-to-date, and I’ll be placing direct links to many of the sites on my appropriate webpages. But I wanted to highlight the main page here. It covers all subjects, and is definitely worth checking-out.