Mikhail Dikov has written a very good article about how to use and deploy global resources within SharePoint.
He uses a Feature Receiver and creates a one-time scheduled job which copies the resource files from the feature folder to the App_GlobalResources folder under Inetpub\wwwroot\wss\VirtualDirectories\[port].

Now, why I'm writing about this?

Because there is one little thing within his code, that makes this solution unusable for a farm with more than one WFE (Web front-end server).
The resource files were copied only on one WFE each time I activated the feature. After searching the web a while, I found that the parameter SPJobLockType is the problem.

In Mikhails solution this parameter is set to "Job", which defines that this job executes only on one machine at a time. In a farm, I want to execute this job on each WFE. So set this parameter to "None" and it works!

Another solution is the article from Maxime Bombardier "Deploying resource files across a farm". For me it seems to be a little bit difficult and more complex than the solution from Mikhail.