To set up Fedora to login automatically just open the file /etc/gdm/custom.conf, and then add the following three lines to the end of the file.
[daemon] AutomaticLoginEnable=True AutomaticLogin=brad
In the above brad is my user name. Obviously you should use the user name you want to log into automatically.
An alternative method is to login automatically after a certain amount of time. To do this use the following four lines.
[daemon] TimedLoginEnable=True TimedLogin=brad TimedLoginDelay=5
The TimedLoginDelay option is used to set the number of seconds to wait until the user is automatically logged in.