Frederick Vandenbosch, who I had the pleasure of meeting at the Raspberry Pi Big Birthday Weekend last weekend, has just written up a great guide to working headless with a Raspberry Pi (i.e. without a screen, keyboard or mouse plugged into the Pi itself). He’s focused on Raspbian Jessie Lite, but it will work with both flavours of the Pi’s favourite operating system, and with all flavours of Raspberry Pi, provided you’ve got wifi capability via on-board functionality or wifi dongle. He goes through the process of downloading and burning the image with Etcher and setting up ssh and a wifi connection. Read the tutorial here.