K-12 resources listed at this site are categorized both by subject (Arts & Music, Language Arts, Math, etc.) and by media type (animations, primary documents, photos, and videos). A search box allows users to enter their own keywords for finding resources. When accessing a new categorized resource such as this, it might be helpful to begin by choosing a category and drilling down to see how information is organized and the types of results within each category.
For example, starting with Arts and Music, a user can drill down to Visual Arts, then to Photography to find 34 resources. Four resources are featured and all 34 resources can be displayed. One of the topics is Mathew Brady Portraits, which is cross referenced in U.S. History Topics and U.S. Time Periods. Users are directed to the Smithsonian National Portrait Gallery and Mathew Brady's Portraits.
Take some time to browse the collections to find quality resources for your students.
Thinkfinity - http://www.thinkfinity.org/
Here is another high quality site where educators can find free lesson plans and educational resources aligned to state standards, provided by partners with expertise in each content areas. Content partners include National Geographic, Science NetLinks, EconEdLink, ReadWriteThink, LiteracyNetwork, ArtsEdge, Smithsonian's History Explorer, Illuminations (Math), EdSitement and Wonderopolis. Resources can also provide parents and students with access to educational content in the At Home & AfterSchool area. Summer might be the time to begin organizing resources to integrate into key lessons for the upcoming school year. Take some time to explore Thinkfinity this summer!
These two resources could keep educators busy during the summer collecting valuable resources to share with students. If you are interested in more information like this, click the article link to read the entire ASCD article and access to additional resources.