My first introduction to the concept of a sculpt map is through Second Life. I have yet to encounter them elsewhere, so I cant give all that much information on thier history, however they were introduced into Second Life in 2007. Working on the principal that color is represented digitally using RGB color space (a group of 3 numbers from 0 to 255, representing the brightness of red, green and blue respectivly), it can be converted to 3-D space (location in 3-D space is represented by values on the X, Y, and Z axis) we can represent a 3 dimensional object using pictures!
Obviously, this method has limitations. The objects made have to have a predefined structure of faces and verticies, that create an even, euclidean place when flattened out. This means that typically, it is very difficult to model things from scratch, and certian modeling techniques are not possible due to the topology. The other biggest drawback is that there is a loss of fidelity, since RGB colorspace is only a cubic grid 255 units wide. This effectivly "pixelates" (or voxelates) all of the models made. This is most obvious on small detals that are far apart from eachother, or smooth curved surfaces.
Still, its less about the model, and more about the maps!
For this project, i used Python to make a script plugin for Blender 2.7x. This script automatically generates the basic primitive shapes that will commonly be used for sculpting: Sphere, Plane, and Cylinder. (other shapes are possible, and a pillow shape was included because I made that one by accident and it was pretty cool.) Simply adjust the X and Y values to match the amount of detail you desire, and hit make. It will generate the prim based on the parameters. The resulting sculpt map will be of the same dimensions.
You can then edit the object using Blender, assuming you keep the mesh intact. Click bake, and it will normalize the object you have made, and create the sculpt map in the UV-Image viewer's image list.
If you would like to try it, run this script in blender! https://github.com/Jeran64/SculptMakeBakeTake/blob/master/SculptMakeBakeTake.py