A volcano in a mug. Neat idea to show kids how they work. Much more accurate than the old baking soda/vinegar idea.
iPads in the Classroom: App Recommendations Galore! Good, extensive list
101 Websites That Every Elementary Teacher (And mom!) Should Know About
CVC Words with trays ... fabulous!
Do your kids like to play with puppets? Mine love them for imaginary play and story telling. Another great rainy day activity! Here's a tutorial on how to make shadow puppets, plus links to other puppet ideas.
50 Inspiring Children's Books with a Positive Message
Content Trailers-short music videos to act as a "hook" when introducing a lesson. All grade levels, all subjects"
Writing Prompts from Photographs: Alligator, Iguana, Man of War and more! (could be used as conversation starters as well)
Kindergarten Sight Word Worksheets | Confessions of a Homeschooler
"Nails for breakfast" science experiment (seeing the iron in cereal)