Shet ben Adom
Shet was the third son born to Adom HaRishon and Chava. He was born 130 years after the Creation and lived to the age of 912, passing away in 1042 to Creation. Noach was a descendant of Shet, making him the father of all mankind since all humanity including the descendants of Kayin perished in the Great Flood.
Shes was born after Adom had done over a century of immense Teshuva. He was called Shes since he was a 'replacement' for his older brother Hevel who had been murdered by Kayin. Additionally, the word Shes is formed by the last two letters of the Hebrew AlepBeit, Shin and Tav, since these were the letters that Adom had managed to rectify through his Teshuva, allowing him to give birth to a rectified son. Shet was born already circumcised.
Hevel was mercy and kindness in comparison to Kayin but he still had good mixed with bad, this was refined in Shet. Unlike his two other brothers who were not created in the form and image of Adom, Shet was. All the souls of the Tzadikim were rooted in the soul of Shet as opposed to the souls of the wicked that stem from Kayin.
Shet married his twin sister and gave birth to Enosh at age 105. Aside from Enosh, Shet had many other sons and daughters.
Shes was considered one of the 'seven shepherds'. He inherited the 'priestly garments' or the position of the leader of the 'Side of Holiness' from his father 'Adam'. Upon his passing, this position was transferred to Mesushelach.
 Kever Shes ben Adom
Shet ben Adom is buried in Arbel, Israel.