At a homeschooling information meeting I organized someone asked “What about science?” “How can a student learn science at home?”
Science is a method. The scientific method allows us a way to know our world, to make discoveries that are testable. Science isn't just what you find in a book of facts. That book of facts is great, but it's just the information we've learned using science. To really understand science you have to practice the scientific method and experience the power of it's application.
That can be done anywhere, anytime. Perception and wonder are a great start. Notice what is around you. Wonder how it got there, what it does, why it does that, how it does that. Observe. Make a guess (hypothesize) and test your guess against reality. Wonder and notice some more.
That said, it does help to have information to fill in the blanks.
Science Crafts for Kids (this one is great!)
Making Things (more artsy, but uses basic principles you can highlight)
Don't forget that children's play is their "work". Science is naturally fascinating.
Here are some sources for toys that reinforce scientific principles