1) There's a super useful Scratch Curriculum guide - made by the folks from ScratchEd. http://scratched.gse.harvard.edu/resources/scratch-curriculu...
2) Blockly seems to be under the Apache license (https://github.com/google/blockly)
Even though Blockly (and it's predecessor, "App Inventor") is made by Google (the great and the powerful), I have to say, I would rather be introduced to code by Scratch than by Blockly. Scratch is much simpler-looking, it has a beautiful interface, and (most importantly) it has one of the friendliest communities in case you need help or want to show off a project.