The Mage Guilds of the Midkemia setting are more like trade guilds than traditional mage guilds. They are generally organized on a city by city basis and are more concerned with price setting and other commercial aspects. They are located in large cities like Natal, Krondor, Rodez, Rillanon. They usually have a small office with some guest rooms and probably a small shop for material components. They do not have research facilities or libraries. Alchemists fall under the authority of the mage guilds.
One exception is the Mage's Academy on the island of Stardock. It is run by a very powerful wizard and he will train anyone as long as they are not evil. There is a small staff and student body of wizards from all over the world and from other dimensions as well.