This is really simple and easy to do, and there are a huge number of ways to do it. This is my method, using
sudo apt-get install feh
Second, configure the wallpaper to be set on startup. For this, we'll need the
~/.xsessionrcfile. Place this line somewhere in
#!/bin/bashbut before the
# Set background image with feh feh --bg-scale /usr/share/backgrounds/warty-final-ubuntu.png &
This just invokes
feh and tells it which image to set as the background. I have the default warty background here, but you can change the file path to any image you want.