There was a pretty good tutorial for Darkbasic classic which can be found here:
http://www.thegamecreators.com/?m=view_product&id=2030&page=3d_tutorial_index
It doesn't work properly in DBPro so I made a few ammendments and have attached it to this post. I've only done the very last tutorial file but that's all you're going to need anyway.
It's probably not exactly what you want as it's a simple first person shooter but a goblin walks about the map following the player so it gives an insight into how to bring a character into the game.
Because it's a darkbasic classic tutorial and a good ten years old, some of the way things are done are going to be different to how someone might do the same thing in DBPro.
The one keep in mind is that it uses a matrix for the terrain and not a model. The very big difference here is that there are commands for calculating the height a matrix if you know the x and z coordinate. If you're using a model, these commands will not work. You'll probably need sparky's collision dll (you should be able to find this on the program announcement board).
Anyway, experiment with code and I recommend reading through the tutorial as well.