I've found a great guide for Internet tethering from Ubuntu. You could use the same guide in Fedora with Gnome or other Gnome-related platform.

If you have a UDP (LAN) wired connectivity or a mobile broadband connection, you could create an ad-hoc wifi network that spreads that internet connectivity. Follow the steps, specifically the ad-hoc and automattic settings, as well as adding a specific WEP-protected password, in order to share the Internet connection to another device.

Keep in mind that 'Shared' option is mandatory for the 'server' and you also have to pick 'ad-hoc' type of network from the other device that you use to connect from.