First goto this page on the oDesk website:
http://www.odesk.com/community/downloads#linux
Click on the link for:
godesk_1.3.2_ubuntu7_i386.deb (for 32 bit OS users)
godesk_1.3.2_ubuntu7_amd64.deb(for 64 bit OS users)
A window should pop up saying "Opening godesk_1.3.2_ubuntu7_i386.deb" if your using the 32bit version.
Click "OK".
Then click the "Install package" button.
The program will now be installed.
Once it has, you won't see an option for it in your Menus, so to fix this open a Terminal window and enter the following:
Which godesk
This command will show the location of the newly installed program. For example:
/usr/bin/godesk
To see if everything is working correctly, enter the following into the Terminal window:
godesk
and the program should start up.
Now close it, and we shall create a shortcut to it in your menus:
Right click on the top panel where you see "Applications, Places, System" and select "Add to panel".
Click on "Custom Application Launcher", then "Add".
The Create Launcher window should open, enter such as the folowing:
Type: Application
Name: GoDesk
Command: Browse to Filesystem>usr>bin>godesk and click Open.
Comment: Something to remind you about it, or you can leave it blank.
Then click OK
You should now see the shortcut in the top menu. If you don't try logging out and logging back in again. This sometimes occurs when installing programs and is nothing to worry about.