After receiving your cuttings in the mail, place them in a bucket of water, about halfway filled. 

Allow cuttings to root. Wait until roots are about 1 inch in length or more.

This process takes about 1-2 weeks to get desired length of roots.

After your cuttings have roots, dig a hole deep enough for the roots to sit in. Cover up roots with dirt.

Proceed to water at least once a day until you are confident they have rooted. 

Planting during a few rainy days if possible would be beneficial to your having to manually water them yourself. 

Space your trees out 3-5 feet from each other.