The first time you checkout the current project to a new workspace, 
you have to prepare it to be able to work easily with maven from
eclipse itself.

Perform the following steps:

1.- Launch the *prepare-workspace.xml* ant build file. 
    You can do it by loading the file into the ant view, 
    and running the default task, or right-clicking the 
    file from the package explorer or the navigator and
    select the option: *Run as > Ant build*. 
    
2.- Restart eclipse.

3.- Import the subprojects of the project you have just checked out.

Those steps are only needed once per workspace.