Learning about science and nature and the world around us is great fun. Here are some websites that will help you to learn all about the how the world works:
BrainPop Junior's cool animations and fun games are a great way to learn.
Get a list of interesting and fun Science websites from Homeworkspot.com.
FirstScience.com is a more advanced site, but with a little help you'll find loads of interesting information here.
ScienceMaster is another page with lots of fascinating information about how the world works.