Talk about the sun because it is the most important part of the solar system. The sun contains 99% of the mass in the solar system, and this mass that gives it enough force of gravity to keep all the other objects in orbit around it. Additional talking points can include the formation of the sun and the rest of the solar system from interstellar gas and dust, as well as what makes the sun a star (namely that it undergoes nuclear fusion in its core).
Move on to the planets. After the sun, the eight planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune) are the most distinct parts of the solar system. Compare the size of the planets. Discuss their classification as "gas giants" (large planets made up almost entirely of elemental gases) vs. the "rocky" planets (smaller planets made from solid elements). Next discuss how all the planets, except Mercury and Venus, have moons. It also is interesting to note that some of the moons' characteristics, like the volcanoes on Jupiter's Io or the thick atmosphere of Saturn's Titan.
Discuss objects in the solar system that are not the sun, the planets or satellites. The sun's immense mass keeps countless asteroids in its orbit, the vast majority of which are located in the asteroid belt between Mars and Jupiter. Next, explain the Oort Cloud, which is beyond Neptune and is believed to be the birthplace of comets. The Oort Cloud also is the home of several dwarf planets, including Pluto and Eris.