Upon first entering Tevrono from the south, but before going through the gates go around to the eastern side of the town to find some Golems along the wall. The Demon Golem here usually drops a Golem Diadem, but not always.
Now go back to the South Gate and enter the town. Immediately to the east of the gate is Tenuta the weaponsmith. After you've completed the Golem quest she'll also provide training in Parry, though her prices are rather steep.
West of the gate is the inn, which is empty except for Ozmo, who's sitting at one of the tables in the common room. Ozmo will sell you maps of Monoroe Province.
North of the inn is General Baziron's office. General Baziron will first give you quest to end the Golem plague, and, if you ask if there's anything else you can do to assist him he'll give you a quest to kill some Golems who are watching a bridge to the south. He'll also tell you about a Mage living in the mountains to the southeast that he thinks might be able to help you.
So now that you have all the information you can get from Tevrono, it's time to head off and find and speak to the Mage.