hidrau,
I have never heard any kind of prophet schools existing prior to around the turn of the era. But, in the first century there were the well known "Schools" of Hillel and Shammai, who lived during the time of King Herod. They had many disciples or students for which there is much discussion in Jewish literature and the Talmud.
See
http://www.jewishvirtuallibrary.org/jsource/biography/hillel.htmlThese two were sages rather than prophets, but they were famous in Jewish history for their "schools."
My first reaction on reading your question was that you must be referring to the "Schools" or "Houses" of Hillel and Shammai.