Castle of Warren
Hidden Cities - 1
This is an introductory stage like the one most RPGs have. The boss is easy, the gameplay is simple, and there's no way to lose, however even this stage hides treasure that you'd miss without this walkthrough.
Your base is the city of Felnamia. The icon for your base and the enemy's is bigger than the normal town or temple icons. You have 1 military unit so far, and it's standing right on top of the city. In the future you would be wise to keep this main unit guarding the base but since you have no other units and the enemy won't come to you you should head north along the road to the city of Daskania (northeast of your base). Liberate it by walking across it, and notice that you get the option to pull a Tarot card. You start the game with eight cards, which you got based on whatever you pulled in the introductory sequence of the game, but you can have a maximum of 14 so go on and take it. Be warned; all Tarot cards have an effect on the liberating unit, and effects can be bad, so don't pull cards if you've already got 14 nice ones.
After liberating the city and getting a card, move northeast, right across the water. You'll notice that you can move across the water but will do so very slowly. This is because your movement type (which you can check by selecting the unit) is not Water. Check the movement type, since it determines what you move fast on. Once you're on the island, walk around and you'll find Zeltenia, a hidden city. Yes, cities can be hidden, and there is absolutely nothing to tell you that they are there. Often check roads with dead ends, because those ends may have cities there.
There will be a sequence and you'll meet Lans, a character with a really good unit. You don't have to deploy him in this stage but do it anyway so you'll know how to. Press X to bring up the menu, select Deploy Unit, and choose one from the list that comes up. You'll only have one other unit so it won't be hard. Notice that deploying units costs money, and the stronger the unit the costlier it is.
Return to the mainland and liberate that little square west of Daskania. It's a Roshfallian Temple, a place where you can resurrect dead soldiers. Unfortunately, they don't pay you any tribute, however units stationed in one will regain lost HP with time (as they do when stationed in towns).
If this is the middle of the night (since OB has a day/night cycle) you might want to wait till daytime. At high noon, your tribute gets paid to you. Selecting a city with the cursor will tell you how much tribute it's going to pay. Your income equals tribute minus unit maintenance, so make sure you have more cities liberated than units in the field and you'll be fine money-wise.
Now go southwest of the Temple to Volzak, or pick up the two hidden treasures. One is on the small island southwest of Volzak and one is on another small island south of your base, Felnamia. The treasures are randomly generated and there's nothing there that might tell you there's treasure there (i.e. they are completely hidden). When you're done with that, go to Volzak.
Warren will appear and spout a bunch of words. You then get to fight him. Note that you have absolutely no control over your units in battle. You are limited to the options in the menu, which can be brought up by pressing X. You can use one of your Tarot cards, as they all have a battle effect, you can switch tactics, or you can run. Switch your tactics to Leader. This makes your spellcasters and ranged attackers concentrate on the leader of a unit, which is extremely useful.
Do not use Tarot cards for this battle, as you don't need to. In fact, use them rarely if ever, since any EXP from enemies that they kill goes straight to your Lord (the guy you name in the beginning, the leader of your main unit), and a high-levelled Lord makes for a low reputation. Besides, Warren is weak. He'll use some magic which will do good damage but won't kill anyone. Sit back and watch him get beaten up, complete the stage and get a nice cash bonus.