Enabling PowerShell Remoting is a simple thing: open an elevated PowerShell console and type:
PS> Enable-PSRemoting -Force
There are two types of exceptions you may encounter. One is complaining about public network adapters. If that's the case, open "Network and Sharing Center", click on "Change adapter settings" in the left column of the dialog window and temporarily disable public adapters. Often, these are virtual adapters from some sort of virtualization solution. Or, in PowerShell v3, use the new parameter -SkipNetworkProfileCheck.
The other type of exception complains about not being able to check the Firewall status. The reason for this is an error in the Firewall binaries that can occur when you are using a language pack. So if your UI is let's say German but your system is English (or vice versa), then this error may occur.
To work around it, log on with a user that uses the native system UI language.
Don't forget to set the following if you want to connect to remote computers using an IP address or outside a domain:
PS> Set-Item WSMan:\localhost\client\trustedhosts * -Force