Carving hands from wood (or any material) is an especially difficult challenge. What you might need is a good reference on the subject -- something like Koch Kolleg 5: Hands. Written by carver Kurt Koch, this volume deals specifically with carving hands using illustrations, photographs, and instructions in English, French, German and Spanish.
Here are the specifics of volume on hands:
Instruction in carving the seven known carved motives of hands: the working hand; the hand of the crucified; open hand of a woman; hand with firm grip, half closed hand, hand grabbing something fine and hand of an infant. 44 pages. Over 340 photos.
Woodcraft is offering a huge discount on this little gem -- nearly 50% off. It's a clearance item, so I may not be available for long. Here is where you can get Koch Kolleg 5: Hands.