I'd like to try building the Bitcoin core source in Windows. The instructive materials I've found take too much for granted. What environment needs to be installed before building? Can it be built in Visual Studio, or is it one of those cross-compilers like MingGW that compiles code originally written for Linux so it can be executed in Windows?
In the past, the standard method of building for Windows has been to use MinGW. Either have MinGW on Windows and compile from within it (may be more difficult) or cross compile it from a Linux environment.
However, fairly recently, support for using MSVC has been added. Although the official binaries do not use MSVC, you can self compile using it. We even have CI that makes sure that everything builds under MSVC.
Instructions and the necessary project files can be found at https://github.com/bitcoin/bitcoin/tree/master/build_msvc
With windows 10 you can now run linux directly on windows with the Windows Subsystem for Linux
or is it one of those cross-compilers like MingGW that compiles code originally written for Linux so it can be executed in Windows?
There is some option to build bitcoin core without MingGW by using cygwin, msys2 or Visual Studio
Here is a complete guide: https://github.com/bitcoin/bitcoin/blob/master/doc/build-windows.md