Great ideas and resource for teaching about materials such as plastic, fabric, wood and metal from science sparks repined by Charlotte's Clips http://pinterest.com/kindkids/sensual-science-charlotte-s-clips/
Materials, Objects, and Everyday Structures
Secondgradealicious: Materials, Objects, and Everyday Structures....a Science Inquiry and sorting different materials
Another Science Center: Marvelous Magnets!
Heidisongs Resource: Another Science Center: Marvelous Magnets!
Sarah's First Grade Snippets: Living and Nonliving
Jeux couleur montessori Plus
Magnetic/Not Magnetic Sort (also see site for Game Board, "Is It Magnetic?"; not free)