While I have never used the online portion for students, it looks like it would be great for programs who use computers. The website serves teachers and parents of children all ages.
Great resource for science fair projects is a major plus and I always recommend parents look at this page when they talk to me about being stressed out about upcoming science fairs with their school aged children.
Without being a member you can download and print 10 pages a month for FREE. So for the longest time I just did this. Then at the beginning of this school year I decided to take the plunge and become a paid member. I love knowing I have endless printable and resources on hand. It's worth the money.
I really think you should head over check things out and start using the free resources when planning for your classroom.