This is a small program written in python to cycle through your wallpapers in a random order.
Add cycle_wallpaper.sh to your path.
Open up randomwallpaper.py and change WALLPAPER_DIRECTORY to your wallpaper directory.
Similalry, set the path for your set command (like nitrogen or xsetroot).
Set CONFIGURATION_FILE to the path you want you configuration file saved to, and the name.
Save your changes and close randomwallpaper.py.
Open cycle_wallpaper.sh. Set ROTATOR to the path to randomwallpaper.py.
If you're using a simple windows manager, open up .xinitrc and add the line cycle_wallpaper.sh time.
Time should be a number of seconds, or a number of units, and a unit. I.e., cycle_wallpaper.sh 1h cycles every hour. cycle_wallpaper.sh 15m cycles every 15 minutes.
If you're using a more complicated windows manager, add the command to the commands that run at startup by either making a new .desktop file or by using the menus available.