Some stuff on wikipedia about them
http://en.wikipedia.org/wiki/MAOI
Have you got any idea what medication they will be putting you on as they are all varied xx
Just as an overview:
MAOI = monoamine oxidase inhibitors
They work by preventing the breakdown of noradrenaline and serotonin, e.g's of these are phenelzine and tranylcypromine
common side effects: low blood pressure, dizziness, lurred vision, insomnia, tremor, sexual dysfunction
they have the potential to react with other medicines, foods containing tyramine and alcoholic drinks