Simple exploration reveals most things. You're meant to discover the five objects while completing other objectives. I've found three so far:
Engineer Sword: Part of the whole "stop the undead uprising" quest line given by Augustus and then Nericon. Entering the Crow's Nest is necessary for a large number of quests.
Zombie Jake Ring: Finding your way into Madam Eve's is easy, and that gets you started.
Halliwell Pendant: This was the least obvious one, however the Anti Demon Grip Spell is quite obvious on the desk near the (essential) Elven alphabet book, and you'll probably be suspicious of Halliwell's room in the inn, anyways.
Basically, simple exploration and completing existing quests gives you much of your direction. But finding those notes for the password without being told where they are (or that the password is in that form at all) relies on a ridiculous amount of sheer exploration it's quite out of place.
