There are no sacraments in Buddhism in the sense they are found in Christianity.
There are, however, many parallels as you can see below. While most usually involve monastics, ordination is the only one that must.
Birth
Pregnant mothers will often go to a monastery and ask monks to chant a special blessing authorized by the Buddha, known as the Angulimala Paritta. Newborns are often brought to a monastery as soon as possible to have monastics chant a blessing.
Illness
When a person is very ill, they may request monastics to visit and give a sermon and chant protective verses. This was common even in the time of the Buddha. The sick person and there family may also chant on their own.
Marriage
Monastics do not officiate at weddings, but couples will often go to a monastery before or after the wedding to receive advice on lay life and to listen to blessing chants.
Going for refuge and taking the precepts
Traditionally, going for refuge to the Triple Gem and undertaking the five precepts is considered conversion to Buddhism. Often lay people will recite them repeating after a monastic but it can also be done alone. This is often done every time one goes to a monastery.
Death
After a family member or friend dies, people will often arrange an alms-giving and share merit with the departed. This is traditionally done after seven days, one month, three months, and at the year anniversary, although the schedule is not important.
Entering the monastic order
There is an official procedure established by the Budddha for novice ordination (leaving lay life) and high ordination (officially becoming a member of the monastic community). This is explained in detail in the Vinaya. This can onlybe performed by ordained monastics.
Study
- The many of the detailed rules for ordination can be found in the first section of the Vinaya
- You can learn about the blessing for pregnant mothers in the Angulimala Sutta, MN 86.