Where to find Fingers and learn thief skills
Fingers is a Shadow in the Old Camp and he can teach us how to picklock chests and how to pickpocket.
Fingers is between the Castle entrance and the Arena. Having the stone entrance in front of us, looking towards Thor, in the area where we also find Diego and Grim, turn 90 degrees to the left and run in that direction. Pass Snaf the cook and Mud, then look on the right. Here we see a small wooden house attached to the wall, and a man with a red armor standing in front of it. He is Fingers.
We can learn something from him to get his approval to join the Camp. I advise to learn how to picklock chests. We can open them without the skill, but this way we will waste less lockpicks. Pickpocketing is not very useful in Gothic 1, compared to Gothic 2 where it makes more sense.
Also read the complete Gothic 1 guide.