I remember I hated drawing hands. To avoid drawing them, I would pose the characters that I was sketching in a way that would have their hands hidden. That saved me a lot of time by not having to draw all those joints and fingers. Now I know what a mistake that was. I did not realized then that I was depriving my character of their expression. It was only through learning and doing 3D animations did I realize the fantastic expressive nature of the hands.
In many examples given in animations, especially from the traditional Disney animators, they show how just drawing the hands and feet alone gave more expression to the character than with the whole body without the hands and feet. In this sketch of Mickey Mouse, notice how the hands and feet alone tells so much about his pose and expression. You can feel the action with just the hands and feet.
The hand with all its fingers, joints, and planes, is a very difficult part of the body to draw. I struggle with it all the time, but when I spend the time on it and get it right, my drawings and characters comes to life. It is definitely the area to concentrate on for your drawings. On my quick sketch of the hand above, you can see how expressive that hand gesture is. With just one hand, you can feel the movement. I feel that the hand (the person) is contemplating.
To practice drawing the hand, you can look for images or better yet just take a picture of your own hands. In whatever lighting situation you might have for the photo, I do recommend that you have enough contrast in your scene. That will help to bring out the complex forms. That means you need to a smaller light source and not large area lights. If the lighting is too flat, the details will get flooded or washed out by the large area lights, making it harder for you to see the forms. Okay, now I am going into photography so I will stop now=).
If you are not doing so already, definitely put more attentions to the hands and feet. It will pay off big time.