Wizards in Polaqu are just like the ones described in the players handbook.
In most places, every large city contains at least a small mages guild. Mages guilds in smaller towns could well just be a few spellcasters who meet up every wednesday for beers and spell component exchange. In metropoli, however, guilds could be so elitist as to only allow wizards of high level or alternatively they could be more open, allowing any spellcasters of any level, and would thus might have thousands of members.
The Zlcak mages guild mainly focuses on combat related spells and hence contains mainly evokers and transmuters. The guild libraries on Thammatek and Jakrimith contain an assortment of these spells, but few from other schools. These guilds, very unusually, will also have sparring rooms and combat pits, where the mages engage in hand to hand battle.
Evgath contains a large number of necromancy guilds. These are generally only open to undead though. There is a lot of good research in the field of necromancy done here, and their libraries contain many exotic necromancy and conjuration spells.
In some areas, spellbook writing will become incredibly expensive perhaps even impossible.
Any wizard who can afford it will get a familiar in Polaqu. These are often Improved Familiars, but not necessarily.