Qualifications
You'll need lots and lots of schooling to become a rabbi. Typically, it takes five years to get a Master's degree in rabbinical studies.
You need to be an expert in Hebrew, Jewish law, Jewish history, the Bible, the Talmud, liturgy, Jewish teaching methods, counseling, Jewish literature, ethics, Israel, Jewish philosophy, and pretty much all things Jewish.
We'd probably just go for a major in jewish humor with an emphasis in Mel Brooks. (Source)
Most Yeshivas require you to spend a year in Israel; all will require you to intern with a Senior rabbi somewhere.