All grades can find quick information from Britannica School.
Designed for grades 5-8, Middle School contains general information, current events, and pop culture.
Kids InfoBits is a great resource for grades 1-4.
The Pro-Quest Science database is best for upper school research. Start with Britannica or Gale Science, and try this if you still need more information.
Use Biography in Context to research people in science fields.
Science in Context contains articles, encyclopedia entries, images, and other resources to help with your research.