Steps to install and setup a cinnamon flavored crouton on a Chromebook Pixel

InstallCinnamonCrouton

# The next command will install a [raring] based ubuntu 
# chroot, named [cinnamon] into the default directory 
# with the targets [core], [cli-extra], [touch], and [keyboard]

sudo crouton -n cinnamon -r raring -t core,cli-extra,touch,keyboard

# Supply your new username and password like normal, and 
# once that finishes, enter the chroot with:

sudo enter-chroot -n cinnamon

# and add the add-apt-repository with:

sudo apt-get update
sudo apt-get install software-properties-common python-software-properties

# then add the cinnamon PPA with:

sudo add-apt-repository ppa:embrosyn/cinnamon
sudo apt-get update

# then install cinnamon with:

sudo apt-get install cinnamon

# It will download and install a fair number of packages. 
# Once it's done though, cinnamon will be ready to run.

# You can download the script I use to start cinnamon.
# first, we want to move to the download directory so it's available to chromeos:

cd ~/Downloads

# then download the gist from [https://gist.github.com/sohjsolwin/5934362]
wget https://gist.github.com/sohjsolwin/5934362/raw/f68fc0942798902a0bd48f40c17dc0cd5cf585ea/startcinnamon

# make it executable

sudo chmod +x startcinnamon

# then we exit the chroot and copy the cinnamon start script to the 
# /usr/local/bin directory so it will run the same as the other chroot start scripts

exit
cd ~/Downloads
sudo mv ./startcinnamon /usr/local/bin

# then we start cinnamon

sudo startcinnamon -n cinnamon -b

# Ta Da!!! And now you have cinnamon croutons. Don't worry if it seems to take a bit to load at first, 
# cinnamon can take a moment or two before it's ready to go. I usually switch back to ChromeOS and
# continue doing stuff for about 30 seconds before Cinnamon is ready to go.