Interesting interactive site for 4-5 grades. Lots of good information, neat pictures and links. This site features a brief biography and photo of any explorer imaginable. Some even include maps portraying the explorers expedition. This mixes social studies facts and competition.
Links are interactive, interesting sites.
This site shows landforms and definitions. This site shows common leaves of Missouri. This is a good site for teaching the solar system. It begins with a review of the planets in our solar system. Then it continues on to cover info about each of the planets.