If you are a home scientist - fascinated with how things works, and curious about fields such as Biology, Geography, Chemistry, Physics, Astronomy (not astrology!), and the Earth Science... then check out these great websites;
Biology: http://www.biology4kids.com/Astronomy: http://www.cosmos4kids.com/Chemistry: http://www.chem4kids.com/Geography: http://www.geography4kids.com/Physics: http://www.physics4kids.com/Don't be put off by the 'for kids' label - these websites are a great place to start or brush up on your science knowledge. They also make a great starting point for more thorough research, and what I like about these websites the most is; they talk in terms of
systems i.e. they explain how things interact in the world - rather than just in a dish, or under a microscope.
If you want to take things a step further, then check out 'The Teaching Company' at
http://www.teach12.com/, however, they are not free. So, you could also check out Wikipedia at
http://www.wikipedia.org/ for free information.
Wikipedia is great as a starting point for further research on whatever topic you're pursuing. I say
starting point because Wikipedia offers external links and references which are sometimes far more valuable than the information listed on the page.
Another great resource for learning is 'Google Scholar'
http://scholar.google.com.au/. Google Scholar is a search engine that lists scientific documents for whatever search terms you use - which is excellent for sourcing evidence (for and against) your research.