Animals

• National Geographic: Animals
• The Natural History Museum: Dinosaurs
• Smithsonian National Zoological Park: Animal Index
• Endangered Species
• Wildinfo.com: Wildlife Fact Sheets

Biomes & Conservation

• Biomes of the World
• Blue Planet Biomes: Biomes of the World
• Camp Silos: From Native Prairie to Present
• Conservation Web Field Trips: Field Trip Earth
• The Dirt on Soil
• EcoKids
• EduGreen Explore
• World Biomes 

Plants

• Biology4Kids
• The Great Plant Escape
• University of Illinois Schools Online
• USDA Plants Database
• Kids Gardening

Earth Science

• Energy Kid's Page
• Geography4Kids
• Internet Geography
• USGS: Water Science for Schools

Weather

• Weather Wiz Kids
• Web Weather for Kids

Planets & Solar System

• Amazing Space
• NASA: Solar System Exploration
• National Geographic: Science and Space
• Windows to the Universe

Science Experiments

• USDA for Kids
• San Francisco Exploratorium: Activities
• San Francisco Exploratorium Snacks: Experiments
• Science Buddies
• Science Fair Central: Project Ideas

Famous Scientists & Inventors

• Great Idea Finder: Inventor Biography
• Inventor Archive
• Windows to the World: People in Science
• World of Scientific Biography