Comment by moftz

It would be even easier and less vague to just pop out the SD card, open up /etc/network/interfaces, and edit that to add your network. Pop it back in and go. This is what I've done when setting up a new raspberry pi image without having any peripherals attached to it. I ssh in, configure the system to my liking, then make an image of the SD card for future use. I could even turn this work into a script that downloads new raspbian images, edits them for my purposes, then packs them up to be used later.