Currently there is Service Pack 1 out for SharePoint 2013 and it can be found here http://www.microsoft.com/en-us/download/details.aspx?id=42008
But as of the writing you still needed to install SharePoint 2013 onto Server 2012 R2 before applying the service pack, which is not support by Microsoft.
Attempting to do so would generate errors related to App Server Role not installing correctly. Below I will show step you through the steps I completed to successfully install SharePoint 2013 onto Server 2012 R2.
In my scenario I wasn’t able to access the internet from the Servers I was installing SharePoint on so I will cover this as an offline install.
1. To install the Roles and Features that are required by SharePoint 2013 on Windows Server 2012 in an offline environment, you must have access to the Windows Server 2012 installation media. You can then run the same Windows PowerShell commands that you used in Method 2, but you must use the -source parameter to specify the location of the required files on the installation media.
For example, assume that you mounted the Windows Server 2012 installation media (ISO) to drive D of the server. Then, the path to provide for the -source parameter is as follows:
D:\sources\sxs
Note Be aware that you can also copy the files locally or specify a UNC path where the installation files are stored.
Open an elevated Windows PowerShell prompt on the SharePoint server (that is, Run as Administrator), and execute the following commands:
Import-Module ServerManager
Add-WindowsFeature NET-WCF-HTTP-Activation45,NET-WCF-TCP-Activation45,NET-WCF-Pipe-Activation45
Add-WindowsFeature Net-Framework-Features,Web-Server,Web-WebServer,Web-Common-Http,Web-Static-Content,Web-Default-Doc,Web-Dir-Browsing,Web-Http-Errors,Web-App-Dev,Web-Asp-Net,Web-Net-Ext,Web-ISAPI-Ext,Web-ISAPI-Filter,Web-Health,Web-Http-Logging,Web-Log-Libraries,Web-Request-Monitor,Web-Http-Tracing,Web-Security,Web-Basic-Auth,Web-Windows-Auth,Web-Filtering,Web-Digest-Auth,Web-Performance,Web-Stat-Compression,Web-Dyn-Compression,Web-Mgmt-Tools,Web-Mgmt-Console,Web-Mgmt-Compat,Web-Metabase,Application-Server,AS-Web-Support,AS-TCP-Port-Sharing,AS-WAS-Support, AS-HTTP-Activation,AS-TCP-Activation,AS-Named-Pipes,AS-Net-Framework,WAS,WAS-Process-Model,WAS-NET-Environment,WAS-Config-APIs,Web-Lgcy-Scripting,Windows-Identity-Foundation,Server-Media-Foundation,Xps-Viewer -Source G:\Sources\sxs
2. Your server may require a restart after you run this Windows PowerShell code.
3. Install the other prerequisites that are required by SharePoint 2013. except App Fabric Setup (See #4) – Found a lot of direct links to download Pre’s here http://social.technet.microsoft.com/wiki/contents/articles/14582.sharepoint-2013-install-prerequisites-offline-or-manually-on-windows-server-2012-a-comprehensive-guide.aspx#Downloading_the_SharePoint_2013_Prerequisite_files_for_Offline_Installation
4. as stated above you will need to run the following in powershell to install the App Fabric software because it requires special settings. In Powershell run .\WindowsServerAppFabricSetup_x64.exe /i CacheClient”,”CachingService”,”CacheAdmin /gac
5. Run App Fab Patch
6. Reboot
7. Run SP 13 Setup
8. Run SP12 SP1
And that will do it.
Good luck.