Fighter/Barbarian/Monk: De'arnise keep. do Nalias quest with the fighter.
Ranger: the Ranger Cabin in umar hills. Talk to the boy delyn or the wizard Tolgerias. both in the goverment district. then talk to the mayor in Umar Hills.
Paladin: not really a stronghold, rather a room in the Order of the Most Radiant Heart building. To trigger, talk to Lord Jierdan in the copper coronet.
Mage/Sorcerer: The Planar Sphere. Talk to Tolgerias, find Valygar, go to the sphere, finish it, take Lavok out. he then lets you keep the sphere.
Cleric: Walk around in the Temple district. Eventually you will run into a prophet named Gaal preaching to the crowd. after that, either the morninglord, the high watcher or the stormlord will talk to you. go to the appropriate temple and speak with the dude.
Thief: A thief's guild. Talk to Renal Bloodscalp in the docks district. An expansion mod available
here. Havent tested myself.
Druid: The Druids Grove and the nifty title of Grand Druid. Talk to the dude standing around in the middle of the city gates. Dont recall his name.
thats about it then. hope it helps [img]smile.gif[/img] .