BBC BitesizeThe BBC's web site has pages on educational activities covering a wide variety of topics. This would be a great place to start any research you have been asked to do
Hertfordshire Grid for LearningHertfordshire LEA has a web site full of information about education and links to lots of interesting sites
GridClub LearningTry this site for fun and games as well as for information for your topics
Topmarks EducationThis site also contains lots of links to useful educational sites
Natural History MuseumThe Natural History Museum, London. Interested in plants and animals? This site is for you to explore