Hercules - An open source System/370, ESA/390, and z/Architecture emulator for GNU/Linux, Mac OS X, and Windows.
Hercules page - Installation, software, and programming guide.
Hercules/390: the New Users Documentation Effort - A volunteer effort by many authors to create a Documentation for the Hercules emulator, coordinated by Cory Hamasaki, divided into Primary, Non-Install and Advanced topics.
Your Private Mainframe - Introduction and links about the Intel-based Hercules mainframe emulator, as well as an MVT tutorial and MVS 3.8 binaries and add-ons.
