Many users try Linux for the first time in a dual boot setup so WebUpd8 reader Satyajit has created a nice dual booting guide to help them get started.
Guide to Dual Booting (PDF) tries to cover the basics: from a detailed Windows, Ubuntu or Fedora installation guide to various issues users may encounter like what happens if you install Windows after Ubuntu and how to get Ubuntu back by restoring GRUB or adding Linux to the Windows bootloader (using an utility that lets you tweak the Windows bootloader, called EasyBCD), which may seem easier for users coming from Windows.
And to make it complete, the guide also covers removing either Windows or Linux from the dual boot setup.
You, the WebUpd8 readers, probably don't need this guide, but I'm sure you have friends who want to try Linux and will find this dual booting guide useful.
Download Guide to Dual Booting
Thanks to Satyajit for the guide and tip!