Would like to get suggestions on what to improve

I bought a new camera last week and I'm trying to learn some about taking photos, tested to take some photos the last couple of days. Please give me some advices on mistakes I'm doing so I can improve my photos.

The current photo can be found at

http://www.flickr.com/​photos/29783237@N05/

Welcome to the POTN. Hope you will enjoy the Critique Corner.

My comments are directed only to the first image - "Bones".

My usual complaint - not enough depth of field. Is that due to taste or just forgot to bring a tripod? The lighting, exposure and color balance are fine.
I think for something this clinical, composition is not considered in the way it would be for fine art.

Thanks for you suggestions, I will start to test some more with depth of field, earlier I had problems with overexposure. But I think I solved that now.

I do not have a tripod yet.

Thanks