docs: Add more docs

README.md

@@ -6,3 +6,36 @@ Files required to build the ubuntu core based pplOS
 
 Everything subject to change, including number of bugs (hopefully to zero ;)
 
+# Building
+
+## System Requirements
+
+To build an image you need to have at least Ubuntu 16.04 on your machine and the following packages installed: `ubuntu-image snapd`
+
+Additionally at least 1 GB of free disk space is required
+
+For virtual device testing you also need `qemu-kvm`
+
+## Other Requirements
+
+ - Ubuntu One account
+ - Snapcraft signing key
+ - Any of the supported boards or at least 4GB RAM free for virtualization
+
+## Creating the image
+
+First run `make` once, it will guide you through the inital configuration
+
+To build a board's model file run `make BOARD.model`
+
+To build an image for a specific board run `make BOARD.img`
+
+## Running the virtual device
+
+Use `make start` to build the amd64.img and launch it with kvm
+
+If you used the defaults in the configuration step you should now be able to connect with `make ssh`
+
+### `Could not access KVM kernel module: Permission denied`
+
+Is your user in the kvm group? Try `sudo addgroup $(whoami) kvm` and reboot.