In what order does one update when including Language Packs? With Service Packs? With Cumulative Updates? It used to be confusing. Now with 2010 it is straightforward.
Get the language packs:
now update your farm as desired.
1- SP SharePoint Server
2- Language packs
3- CU SharePoint Server
4- PS Config (on every box)
NOTE: if you go and add a new language pack afterwards, you must reapply the CU as it may include updates for that language pack. (and rerun PSconfig again, of course)