There is currently no one-document user guide for VINE available which would describe everything in detail in just one place. Nevertheless there is a good amount of documentation available with the code and this page should serve as a reference point for where to look when you search for something in particular. Some time in the future, there might be one user guide document containing all the available info.
Listed below are the main resources of documentation, given with their path:
This is the main README file for the code. It describes how to compile the code, gives some short info about what is in which subdirectory and some basics about code data structures frequently used.
This file contains a complete description of the parameter file read at runtime, which is called insph. This is probably the piece of documentation which will be most used as the runtime switches determine the behavior of the code and most often, you will be changing parameters in here (apart from recompiling the code to include, e.g. other sets of modules for different kinds of scientific applications).
This file gives some advice how to create a simple initial condition using the routines supplied in the init directory. Basically those routines should only serve as an example for how to get an initial condition file written which has the right structure for VINE.