Last updated: 16 March 2019
Hi! This article now lives at https://jonatack.github.io/articles/how-to-compile-bitcoin-core-and-run-the-tests where I will continue to update it. Cheers.
This is a simplified compilation of the various docs in https://github.com/bitcoin/bitcoin/tree/master/doc. Don't hesitate to read them for more information.
All steps are to be run from your terminal emulator, i.e. the command line.