You can use the Textbook-Integrated Guide to Educational Resources (TIGER), hosted on the ChemEd DL to help you locate resources. There is also a Search option in the menus on the home page and you can browse through the list of the ChemEd DL’s top 10 resources.
You can use the NSDL general search or their advanced search. You can also browse resources using the Science Literacy Maps. These allow you to use the AAAS Project 2061 Benchmarks to find related NSDL resources.