Creating homebrew programs for the Nintendo 64, is both easy and hard. It's easy to make a "Hello World" program, but to truly use the hardware available will take some real initiative.
I had a bad experience getting a working N64 toolchain. I hope the following information can prove helpful and save other some frustration. I consider this current as of Sept 2018.
Linux toolchain Options:
Windows toolchain Options
MacOS toolchain Options
Development Libraries: