Solar System Search
To do my search I went to http://www.google.com and did a search on "planets". The Nine Planets site was the first on the list. I found the rest of the sites here from the list of links at The Nine Planets site.
1. Exploring the Planets - http://www.nasm.edu/ceps/ETP/
This site, supported by the National Air and Space Museum, focuses on the history and achievements in the exploration of our solar system. This site was organized very logically and there were links on every page to make moving back and forth easy. There was only one drawback to the organization I would note. There were a couple sections that didn't seem to have enough information in them to warrant it being a separate section. A couple of features of this site are a map of the actual exhibit in the museum. You can click on various parts of the map to go directly to that section of the exhibit. Another feature that I thought was particularly interesting was the activities section. It seemed this part is still being developed, but it has a good start and will be a valuable part of using this web site in the classroom in the future. The activities section includes activities that are directed especially to teachers and students. They include full lesson plans for the teacher and detailed instructions for the students. Right now there is only one lesson plan available, but there will be more added periodically. Eventually there will be lessons of varying levels available. I think the activity I looked at is definitely something I would use in my classroom, so I'm sure when more are added, this site will be a very valuable resource.
2. Views of the Solar System - http://www.solarviews.com/
This site has information on the solar system as a whole, each of its components, history, and latest discoveries. This site is organized very well especially for the amount of information it contains. One of the features of this site is that it is offered in five languages (English, Spanish, Portuguese, French, and German). Another feature of this site is simply the vast amount of information it presents. This site could be very useful in the classroom if presenting the solar system as a whole or for more detailed information on particular planets, stars, etc. This would also be a good site for independent student research.
3. Virtual Solar System - http://www.nationalgeographic.com/solarsystem/
This site is presented by the National Geographic Society. The main feature of this site is the opportunity to take a 3-D tour of the solar system. However, this is also a drawback, since there has to be special software downloaded in order to use this feature. Also the software cannot be downloaded to Macintosh computers. There is a 2-D version provided for Mac users or those not wanting to download the software required for the 3-D version. I felt the 3-D version gave an interesting perspective that often isn't presented when studying the solar system. I think the students would find it useful as well, IF the school were equipped to use this site, however, most schools have a primarily Mac platform.
4. Star Child - http://starchild.gsfc.nasa.gov/docs/StarChild/StarChild.html
This site is a project under NASA and provides information about the solar system. The entire site is designed especially for children. I think it's organized very well with several links to move around the site easily. I think this site would be useful for younger students particularly who are just beginning to learn about the planets and the solar system. It provides a link to another site for ages 14 and up (Imagine the Universe).
5. The Nine Planets - http://www.seds.org/nineplanets/nineplanets/nineplanets.html
This site is basically and overview of everything that is known about our solar system today. There is a separate page for every major body in the solar system containing several pictures, scientific and historical facts, links to related pages (for example each planet page has links to pages about each of its moons), and links to pictures at other sites. This is a very extensive site and is organized very logically. Some of the features it includes are video clips, sound clips from Holst's The Planets, a glossary of scientific terms, and sound clips of pronunciations of unusual terms. It includes a large list of links to other sites featuring the solar system that the author feels are the most useful. Included in that list is another site directly related to this one that I think is the best feature for incorporating this into the classroom. There is another version of The Nine Planets that is designed for children. It contains much of the same information, pictures, videos, and sound clips but has been scaled down a bit. For younger students this kids' version is a very good site for learning about the solar system and as they learn more they can progress from the kids' version to the original for even more information.