If I understand the question, you want to know how to put a shortcut to Firefox on your desktop.
To do this, right click on the desktop, click New, click Shortcut. Next, you will have to browse to the executable file for Firefox. Click Browse, then Computer. Next click the C: drive, scroll down and click on Program Files. Scroll down and click on Mozilla Firefox, find the firefox.exe file, select it, then click OK. In the Create Shortcut dialog box, click Next. Type the name you want to display under the shortcut, then click Finish.
Short (easier) answer:
Click the Start button at the bottom left corner of your desktop. Click Programs or All Programs (depending on which version of Windows you have). Scroll down until you find Mozilla Firefox and click on it to open the folder. Right click on the Mozilla Firefox link, then click Send to. Click on Desktop (create shortcut).
This works for Windows. I do not have the answer if you have a Mac or Linux based system.