Our Military Kids: has extracurricular scholarships specifically for Guard & Reserve children.
Tutor.com for Military (currently also includes DoD Civilians): free online, on-demand tutoring for military families - service member, spouse and children.
United Through Reading: families can read together even if the service member is deployed.
Military Family Books: great place to buy military specific books.
Military Kids Connect: Defense Health Agency sponsored and moderated forum where military kids can connect with other kids, watch videos about going through various challenges, etc.
Comfort Crew Kits: free kits that address deployment, grief, transition, and more. Resources for students and parents that can be ordered directly by military families.