If you are looking for a project that will interest an adult, you should check out About.com. They have a variety of projects for both adults and children. The great thing about these projects is that they actually teach you something about the Solar System like the project that helps you learn the constellations, which is great for school or a hobby.
NASA is one of the best resources available for anything space related. It has special sections for children and students of all ages so whether you are a middle school student looking for a science fair idea, a college student searching for research materials for a term paper, or an amateur astronomer looking for the latest news and project ideas, there is something for everyone. You can even contact NASA to get a guest speaker at your school and look into applying for their youth programs and internships depending on how old you are.
There are also many space projects for children and some that you will enjoy too. How Stuff Works has interesting projects that will interest both children and adults. For example, they show you how to make an astrolabe, which is a tool used for centuries by sailors to measure the position of the stars and help navigate. The website also has a project to help you memorize the constellation, which makes gazing at the stars a much more pleasurable activity.
Discovery Education has great ideas for reports. While these ideas are geared towards pre-teens and young teenagers, they can be modified for younger or older age groups. Even adults will be tempted to check out some of these links. This website also has other resources including quizzes and activity sheets. These are just a few of the place to find great resources and ideas on Solar System. Start here and continue the search for great space projects and ideas.
Universe Today has articles on all the planets and Solar System worksheets.
Astronomy Cast has an episode on each planet including Jupiter.