e said, first you have to get the Conky files installed.
Go into the Synaptic Package Manager and search for > Conky
Select to install Conky and it's dependancies.
Now, you need a Conky Script
for the OS/WM to read.
You might look for a script you like in:
Official Conky site >> http://conky.sourceforge.net/
LinuxMint Conky thread >> viewtopic.php?f=60&t=30209&start=0&hilit=conky+showoff
Now, that you have selected a Conky script you like, copy and paste
it to your text editor ... you need to save this file as .conkyrc
Now you can post the Conky to your desktop, by opening a Terminal and type: conky (no 'sudo' involved)
Your new Conky should pop-up on your desktop.
When you want to change or modify Conky, simply open your File Manager and under 'View' tab in the taskbar select 'Show Hidden Files' ... scroll-down to .conkyrc and open it.
You might also, have a look/see at http://conky-artists-group.deviantart.com/
(I am an Admin of the DA Conky Group)