Note that this does not include the SKSE source code.

You will first need to get it from http://skse.silverlock.org/

The path structures are relative to /src/ of SKSE

The common directory only includes projects intended to build on:

Visual Studio Runtime 2013 (vc120)

Visual Studio Runtime 2015 (vc140)

All runtimes are build statically.

Some projects may be built for vc120, others may be built with vc140, though many will likely build with vc140 anyway.