What, if anything, must be included with a project regarding how to compile it, to be fully GPL v3 compliant? For example if I'm using Netbeans and simply use it to compile and run the code, what kind of documentation would be required? The code is intended to work without any special compiler instructions (unless so desired).
The best way is to think this way:
If I receive this code, which concise and accurate instructions would I need to be able to re-build the binaries from sources?
I should not assume that the recipient knows nothing about software and nothing about Java in this case. Instead I should provide the simple and good enough instructions that a basic software developer could understand and follow to rebuild from sources.
This becomes much simpler: I can simply state in a README that I used Netbeans Vx.x (and may be provide the Netbeans project files) or that I compiled the code with Maven (and provide a pom file) with Java 8 (and provide a link to fetch an OpenJDK 8). If this was built on Linux, I may also provide a list of required packages to install.