Free STEM resources for early elementary age

[believer]

Hi, I am now an assistant youth librarian and am part of a team that is creating a webinar that people will be able to do online and get continuing education credit. Our library has already made a set of early literacy webinars http://www.friscolibrary.com/earlylitclasses and our next set will be about STEM education for preschool and early elementary school children. We anticipate our audience will include daycare providers and preschool teachers, homeschooling parents, parents, and perhaps others. Right now we are researching why and how to include STEM activities - my area is the early elementary ages kindergarten through 2nd grade. Do y'all know of any good websites that I can look at to add to our information? We can't use or recommend things that cost money - it has to be free.
Thank you!

[Anne Ofalamo]

http://allinonehomeschool.com/
I used this for my now 7 year old, it is great, free and although the math was Meh..I loved the reading and so did he!