This is what I know and I am too lazy to find/post a reference.
It is strongly disliked (from a religious point of view - it may even be bid'ah [innovation]) to divorce someone by saying Talaq Talaq Talaq at once.
The proper procedure to divorce is to say (while in your sane mind) Talaq once.
The conditions are:
- The woman is not menstruating
- The man has not had sex with her after her previous menstrual cycle ended.
- She must not be pregnant. If she's pregnant, you cannot divorce her.
After the first talaq, husband and wife can still try to resolve their differences but after all 3 are given, the women has to marry someone else before she can remarry the former husband.