So im learning how to do Macro shots

If you havent been reading, I have just purchased a camera, with which I am diving head first into the world of photography. I have never been really into the whole photography scene, but im hoping to change this as I learn.

As you can see, the camera I am using is far from professional material, but it is perfect for a learner. I have most recently been playing with the macro settings on the camera, trying to take some good macro shots. I have since learned that lighting is paramount to taking good macro shots; poor light ruins the photo, too much light washes the subject out completely.

Below are some macro shots that I have taken. Some show how too little light ruins the photo, but others I am happy with.

My favourite is the picture with the circles. Its from a book im reading. I think it turned out pretty good! Its a learning process for sure, so feel free to give me any hints or tips that may help me to take better macro shots. Constructive criticism is always welcome!