Before you know it, you'll be setting up that sign your kids have held since kindergarten to take those all-important first-day-of-school photos.

But first, make sure that they're prepared with school supplies.

Costco member Caroline Farkas, a former classroom educator and the founder of the educational company Doodles and Digits, LLC, says shopping early is crucial. "My students usually had preferences about what types of items they liked—favorite colors or certain styles," she says. "August usually also has the best back-to-school sales!"

Farkas recommends a general list of school supplies for students of all ages.

For specific age groups, Costco member Julie Cole, co-founder of Mabel's Labels and an award-winning and bestselling parenting author, advises, "Having a list and starting early means you don't have to rush around at the last minute." You also avoid the risk of items being sold out before the first day of school.

The following lists, organized by level of education, can help you pick up everything you need (for a discussion of tech items for college students see Tech Connection).