Take it or leave it. This is from my experience from taking photos:
I would suggest enabling the grid view in your view finder for your camera. This will help you with a couple of things
A) it will help you take your pictures straight and not at an angle. Unless that is your intention
B) it will help you with the Three-Fourths Rule and the placement of your subject. Whether it be a thing or a person
C) It will help you take better portrait pictures
I would say get very familiar with White Balance. Your D7000 has many settings. Unless you are going to tell your camera what the White Balance is every time you go shooting, I would suggest setting it to K (Kelvins). This will help capture the images that you want and give them a pop. You can use your Live view to adjust your white balance to see what the picture will look like before you take it. Auto for white balance works well but in order for it to work as intended, you need an object to be white in the picture. Otherwise the camera, based on what it sees, will calculate what the white balance needs to be and apply it upon taking the picture.
For your first picture, I really like it a lot. But it seems you had your ISO set a bit to high for day time. I say this because your sky is grainy. Your others pictures do not seem to have this problem.
And a good program to use for editing picture that makes things easy for anyone is Adobe Lightroom. I have an example from your pictures on what the program can do.
Other than that, I enjoyed looking at your pictures. Oh and just to make sure I am not full of it. here is a small sample of my work. Enjoy
Oh and one more thing. What type of lens did you use? 18-55mm
