Here is the delayed post about the bi-monthly cumulative updates as usual. Due to some lack of time, I'm referring to the posts of my colleagues, Joerg Sinemus and Stefan Gossner to this topic.

Just for your convenience, I'll copy over the most important parts and adding some of my standard comments related to.

 

Quick Jump:

 


WSSv3/Moss 2007:

Preparation:

It is recommended to stay in a consistent update chain and having the latest service packs according to the cumulative update packages installed.

Before installing CU's:
As per Stefan Gossner: 
Important: this is a Post-SP3 hotfix. It is highly recommended to first install Service Pack 3 of WSS 3.0 and MOSS 2007 before installing December 2011 CU

WSS (12.0.6656.5000):

2596987 The full server package for WSS
http://support.microsoft.com/default.aspx?scid=kb;EN-US;2596987

MOSS (12.0.6656.5001):

2596986 The full server package for MOSS
http://support.microsoft.com/default.aspx?scid=kb;EN-US;2596986

 

As usual:
After installing the cumulative updates, run the SharePoint Products and Technologies Configuration Wizard or
“psconfig –cmd upgrade –inplace b2b -wait” from an elevated command line.

This needs to be done on every server in the farm with SharePoint installed!

For all previous updates and service packs, please see the  “Build Numbers and Cube Sheet MOSS/WSS

Related Links:

Related Update and resource Centers:

More information and Details about SP3 for WSS and MOSS:
http://blogs.msdn.com/b/joerg_sinemus/archive/2011/10/28/wss-and-moss-october-cu-and-or-service-pack-3.aspx


SPS 2010/Foundation (WSSv4):

Ee721049.note(en-us,office.14).gifNote:
It is recommended to install first the Service pack 1 for SharePoint 2010 and Foundation.
Consider the dependencies with already installed Language Packs and maybe having Office Web APPs as well!
Please see the related information here: http://blogs.technet.com/b/steve_chen/archive/2011/06/07/3433939.aspx

December Cumulative Update for SharePoint 2010 is a Post-SP1 hotfix. Ensure that SP1 is installed before the December CU!

 

MSF2010 (14.0.6114.5000):
2597058 The full server package for Microsoft SharePoint Foundation 2010
http://support.microsoft.com/default.aspx?scid=kb;EN-US;2597058

Download link: http://support.microsoft.com/hotfix/KBHotfix.aspx?kbnum=2597058&kbln=en-us

SPS2010 (14.0.6114.5000):
2597014 The full server package for SharePoint Server 2010 and contains also the MSF2010 fixes so you need only this one package.
http://support.microsoft.com/default.aspx?scid=kb;EN-US;2597014

Download link: http://support.microsoft.com/hotfix/KBHotfix.aspx?kbnum=2597014&kbln=en-us

 

Further instructions and information:

After installing the packages, you may be prompted for a reboot of your Server! Please don’t forget to run the PSConfig Wizard anyway, even after reboot just to ensure that all updates has been applied completely and successful! As usual, you can use the command line on each server in Farm:   “psconfig –cmd upgrade –inplace b2b -wait”

Q & A:

Q:  Do I need to install the foundation packages first and then on top of it the server packages?
A: 
No, you can apply directly the Server packages only because they’re containing the Foundation fixes as well. But for a consistent and “save” update process, we recommend always to install the foundation packages + the server packages. In future it could be possible due to any kind of changes, that a certain update level is mandatory to apply later CU’s or that some dependencies might exists between the two package bundles. Also there is already a lot to consider just about language packs etc. as described in my other post here.

Q:  Is the service pack 1 a MUST HAVE before installing any other CU?
A: 
No, you can apply any CU since RTM directly to SharePoint without having SP1. The service pack mostly adds extended features and includes also all fixes until April 2011 CU. But the recommended way is to install the SP! + the latest available CU on top to it just to stay save on your update process overall and for future.

Q: Do I need to install the updates or service packs for each language I have installed additionally?
A:
The Cu’s are usually global and will fit to mostly all languages, so there is no need here. If there will be a CU for a particular language not covered as usual, this will be provided separately.
For Service packs: Yes, each service pack is only for a single language. The SP-Language is relying on the language, your SharePoint has been installed initially. SO if this was English, then the English SP applies, If this was German, the German SP applies, a.s.o.  - For any other language pack you have installed on top of SharePoint, you don’t need to install the Share Point service pack for this languages BUT you must install the language pack service packs according it! See more here.

Other related Links:

Related Update and resource Centers:

 

Acknowledging:

Joerg Sinemus' post:   
- WSS and MOSS December 2011 CU
- SharePoint 2010 and December 2011 CU

Stefan Gossner's post:
- December 2011 CU for SharePoint 2007 has been released
- December 2011 CU for SharePoint 2010 has been released