Carving Hands
When I first started carving human figures carving the hands was one of the things that gave me the most trouble. Chances are I'm not the only one. I thought I would give a short little tutorial on some of the tips I have picked up over the years in regards to carving hands. I have added some directional arrows to some of the pictures below to help clarify the tips and show the directions I usually make the cuts described. I hope these tips will be of some help to you.
Finished Hands
Well that is how I carve hands. This same basic process can be used for hands in almost every position, as seen by the hand holding the book at the right. If this technique has helped you, I would suggest that you experiment with it on a few pieces of scrap wood. You will probably develop your own little nuances and refinements. I'm still learning things about carving hands every time I carve a pair.

Step 5: Knuckles & Fingernails

Now for the final details. I use a small 2mm v-tool to slightly etch in the wrinkles for the knuckles and fingernails. I generally just use about three very shallow cuts for the wrinkles on each of the knuckles. The cuts for the fingernails are also to be made very shallow. In fact, on smaller carvings I sometimes use my own fingernails to press in on the knuckles and fingernails of the carving instead of using a v-tool. This works great on basswood which is soft enough to leave a permanent indention.

Step 4: Ends of the Fingers

I use a v-tool to make stop cuts for the ends of the fingers. When making these stop cuts I hold the v-tool at an angle so that one side acts like a chisel on the side of the longest finger and the other side slightly rounds the inside tip of the finger next to it. With the v-tool held at this angle, I carefully push straight in, not too deep or it will leave a scar on the body. Once these initial stop cuts are made, I use the narrow (7mm) #3 gouge to round the ends of the fingers.
This same basic process is also used for the end of the thumb.

Step 3: Rounding the Fingers

I use a couple of steps to round the fingers.
First I use the same v-tool as I did to separate the fingers to follow the same cuts, except this time I follow each cut with the v-tool laid at a slight angle. This keeps the separation line defined and shaves a little off the side of each finger, beginning the rounding process. This means I am going over each separation twice.
Next I use a narrow (7mm) #3 gouge to round over any hard edges on the sides of the fingers and thumb.
Step 2: Separating the Fingers
Before I start separating the fingers I  remove the excess wood from the sides and ends of the hand. Now I'm committed, this is one reason the drawing and establishing the planes between the knuckles is so important at the beginning.
Next I use a small #11 veiner to separate the knuckles where the fingers meet the hand; not a deep cut, just enough to separate.
I then use a medium size v-tool to separate each finger and the thumb. Notice that I have three arrows between the fingers and two between the thumb and the hand. I did this to emphasize that I make three separating cut for the fingers and two for the thumb. I cut just slightly deeper in the planes than I do at the knuckles, this makes the knuckles seem a little more pronounced as they are anatomically. Finally, separate the thumb from the body using the same v-tool.
Step 1: Drawing the Hands
& Establishing the Planes

Before I start carving anything I like to first lay it out with a pencil. This helps me have the proportions and shapes in my eyes, as well as my mind. If my mind gets distracted my eyes will be able to pick up the slack.
Notice the different lengths of the fingers. Also notice the way the knuckles are laid out; the row of knuckles where the fingers meet the top of the hand corresponds with the first knuckle of the thumb, the first row of knuckles on the fingers correspond with the end of the thumb. This is not a hard and fast rule, it just gives a good starting point for proportioning the thumb with the rest of the hand. Once the hand is drawn, I use a large #3 very shallow gouge to flatten the planes between each row of knuckles, as shown by the arrows.