Art
National Gallery of Art - Lesson plans, activities, and videos for grades K-8.
Google Cultural Institute - "The Art Project features interior tours of seventeen world famous art museums. Simply select a museum from the list on the homepage and you can virtually tour it using the same interface used in Google Maps. The website also offers an option to create your own art gallery while visiting each museum. You can see works of art in greater detail, add to your collection, and open background information about each piece with just a few clicks of the mouse." - http://www.aaeteachers.org/index.php/blog/701-online-resources-for-art-teachers
Art Resources for Teachers - "Teacher Vision is a great resource for teachers of all subjects. For tools specific to art instruction, the website provides an extensive list of free lesson plans, printables, activities, quizzes, and references, perfect for art teachers at the elementary, middle, or high school level." - http://www.aaeteachers.org/index.php/blog/701-online-resources-for-art-teachers
Museum of Modern Art - Free resources for teachers of art.
Guggenheim Museum - "We have designed this area of the museum’s Web site to provide teachers with curriculum materials to support the use of the Solomon R. Guggenheim Museum’s exhibitions and collections both during school visits and in the classroom. This site concentrates on recent exhibitions, but our aim is to develop a comprehensive range of lessons for educators on art and artists in the museum’s collection." http://www.guggenheim.org/new-york/education/school-educator-programs/teacher-resources/arts-curriculum-online
Technology
Schooltube.com - "It's a safe, moderated environment where students can post self-produced videos for classroom use: from the educational (a civics presentation or algebra class) and practical (morning announcements) to the fun (last night's girls' soccer game). Although you might not find video content that will help you teach (because it is all very specific to classes and schools), this is a great tool for giving your students a safe platform to share their creations." https://www.teachervision.com/educational-technology/teaching-methods/71463.html?page=3
Storybird.com - This is a great tool that allows students to create online books. The one negative to this site is that you are limited to art (you have to use what they offer), but it is free.
Kidblog.org - "Interested in starting classroom blogs to improve student writing skills but not sure how to keep your class in a safe environment? Kidblog is a simple blogging platform with advanced privacy features appropriate for elementary and middle school students; teachers have administrative control over what gets published—and what doesn't."
Code.org - Completely free website that teaches the basics of coding to students beginning in kindergarten. The lessons are essentially self-guided and self-paced with activities built in periodically that allow students to physically act out what they need to do in their coding to help strengthen the lesson. You don't need to do any planning or need to know anything about coding to facilitate the learning. This site allows you to create a class and then you are able to monitor their progress from a summary screen.
CodeCombat.com - Completely free for teachers (and students). Students learn how to code by playing a game. Somewhat addicting! Recommend starting with Code.org before introducing this to your students.
Scratch - " With Scratch, you can program your own interactive stories, games, and animations — and share your creations with others in the online community. Scratch helps young people learn to think creatively, reason systematically, and work collaboratively — essential skills for life in the 21st century. Scratch is a project of the Lifelong Kindergarten Group at the MIT Media Lab. It is provided free of charge."
PE
Shape America - Sponsored by the American Heart Association, contains activities and lesson plans for K-8 students.
PE Central - This website offers lesson plans, assessments, classroom management suggestions, challenges and other resources to help the pe teacher have a great class.
The Physical Educator - Offers a tremendous amount of resources for the PE classroom.