Resources
Many specific resources are on my Pinterest page.
My favorite sites, in general:
Khan Academy
Create a free account with your child and watch them rack up points and cool badges on their profile page.
Prodigy
Watch your child become a math wizard, solving problems in order to cast spells and collect treasure.
Math Aids
Create worksheets, including answer keys, to use with your child. They can even play teacher!
Achieve the Core
See what your child is expected to learn at his/her grade level and what each concept is built on.
Podcasts
Huberman Lab - Health science, especially brain science.
Truth for Teachers - Tips and motivation for educators.