You can find the encyclical here:
www.vatican.va/holy_father/pius_xi/encyclicals/documents/hf_p-xi_enc_19351220_ad-catholici-sacerdotii_en.html
All 92 paragraphs of the document are worth the read, but if that is too much, let me recommend the following few paragraphs.
Paragraphs 23, 24, and 25 describe the ministry of the priest.
Paragraph 40 describes the necessity of chastity.
Paragraph 54 explains the necessity of discipline--obedience.
Paragraph 85 explains the holiness of life that is expected of the priest.
In this time of struggle for the Catholic Church, please pray for all of our priests and bishops.