General Resources

MSBuild Source Code

https://github.com/dotnet/msbuild
https://source.dot.net
Use referencesource.microsoft.com or sourceroslyn.io/ to browse Microsoft MSBuild targets. Examples:
- search for "_FindDependencies MSBuildProperty"
- find targets referencesource.microsoft.com/#MSBuildTarget=ResolveAssemblyReferences

Third-party tools:

MSBuildStructuredLog
- A log viewer that displays a structured representation of executed targets, tasks, property and item values.
MSBuildExtensionPack (also via NuGet)
- Provides a large collection of MSBuild Tasks, MSBuild Loggers and MSBuild TaskFactories.
MSBuilder
- Reusable blocks of MSBuild helpers; MSBuilder's goal is to provide fine-grained nuget packages that can be installed when only a certain MSBuild extension (task, property, target) is needed.
MSBuildExplorer
- Use MSBuild Explorer to help you find your way around the make-up of your build file(s).
MSBuild Sidekick
- MSBuild Sidekick allows you to view, edit, build and debug Visual Studio projects and solution files as well as custom MSBuild projects.
MSBuildDumper
- Very quick tool to dump properties and items of a project without building it.
- Install from Chocolatey cinst MSBuildDumper.
MSBuild Profiler
- A performance measurement tool for MSBuild scripts. MSBuild Profiler shows a graphical performance output for all your MSBuild scripts.
MsBuildPipeLogger (GitHub)
- A logger for MSBuild that sends event data over anonymous or named pipes.
MSBuild Shell Extension Note: Not supported on Windows 10.
- Lets you build Visual Studio solutions and projects as well as any MSBuild file through a context menu without opening Visual Studio.

Inside the Microsoft Build Engine: Using MSBuild and Team Foundation Build (2nd Edition) by Sayed Hashimi, William Bartholomew
MSBuild Trickery: 99 Ways to Bend the Build Engine to Your Will, by Brian Kretzler