The DLR has published some iformation on the selection process, however not to much in English. So I briefly translated the most relevant parts, which you can read below.
"If you already hold an ATPL or are shortly about to be given one you will take part in a selection process for pilots (so called ready entries). The whole process will then comprise a basic examination (Ger. Grunduntersuchung) and a company specific examination (Ger. Firmenuntersuchung).
Part 1: basic examination
The basic examination takes one day. Tests for certain aptitudes will be done at computer monitors:
- knowledge of the English language (vocabulary and grammar),
- technical knowledge and physics,
- aeronautical knowledge,
- mental calculus,
- memory span,
- concentration and observation,
- three dimensional thinking,
- eye-hand co-ordination and multitasking,
- personality test.
Between basic examination and company specific examination there will be a simulator screening, which will be conducted by the airline.
Part 2: company specific examination
During the company specific examination additional aspects are looked at which are essential for the work for relevant airlines. The programme takes two days. On both days there will be cuts.
Day 1:
Dyadic co-operation test (DCT). A task to solve a problem, alone and in teams of two.
Behaviour orientated personality dyagnostics (VERDI). Two characteristics are looked at here, social competence and competence to act. This test comprises a difficult conversation, which will be held with an employee of DLR, and two tasks for groups.
Cut: if positive then day 2.
Day 2:
Interview."
Prepware is offered in Englisch here:
http://www.skytest.de/english
Courses in German are offered here:
http://www.sundptraining.de
http://www.topilots.de
http://www.attc.de
German forum with countless threads on all tests DLR offers:
http://www.pilotenboard.de