Have you ever want to learn something, like history, economy, science? Crash Course is a free learning channel on YouTube with many courses for kids and adults, and they just added a new channel specially designed for kids: Kids Science. Great learning resource leveraging the new technology, for school supplements, or for homeschool.
Not sure that there really is a 'legal' way to download music without paying for it. Unless you go to bandcamp and an artist has a pay what you want that starts at $0. http://bythebirch.bandcamp.com/releases