The important ceremonies among the Sikhs are those associated with Birth, Naming the child, Amrit (Baptism), Anand Karaj (marriage), and death. The most important among all of these is the Amrit ceremony.
No special rituals are attached to these ceremonies. The only important aspect is recitation of Shabads (hymns) from Guru Granth Sahib.
The dead amongst the Sikhs are cremated and their ashes are thrown into the nearest canal or river. No sanctity is attributed to any particular river or place. It is forbidden to erect monuments over the remains of the dead.
All these ceremonies have a common objective, namely to remind us of one’s relation with God. These are conceived as means to an end–the union of the soul with the Lord.