Here is a handout about Patriarchal Blessings for you if you want it for a Family Home Evening, YM or YW lesson, or just for your own personal use.
A patriarchal blessing has two main purposes. First, the patriarch will be inspired to declare your lineage—the tribe of Israel to which you belong. Second, guided by the spirit of prophecy, the patriarch will pronounce blessings and may also provide promises, cautions, or admonitions that apply specifically to you. Your patriarchal blessing may point out certain things you are capable of achieving and blessings you can receive if you exercise faith and live righteously.
Why is lineage important?
Every member of the Church belongs to one of the twelve tribes of Israel. Those who aren’t literal descendants are “adopted” into the house of Israel through baptism. Knowing your lineage can be a helpful guide in your life, because belonging to one of the twelve tribes brings the blessings and missions specific to each tribe. The blessings Jacob gave his sons (the heads of each of the tribes) can be found in Genesis 49 [Gen. 49]