If this is your first try you did a real good job. I like the 'village' best, it looks like you realy put some good effort in it.
As for the first picture, make it less rocky.
And your last picture with the lumber mill also looks good, the stairs don't realy fit in but it's nicely made.
The only real bad thing is the bones in your last picture, the dirt around the bones does not match with the ground. If it were me I would remove it but perhaps other people like it. =)
@ Gilles, first picture seems to be art terrein, and the other two pictures give me a rpg terrein feeling. ^^