There are 12 main universitarian organisms offering financiary help in Germany :

Name Link
1. Cusanuswerk Link
2. Evangelisches Studienwerk e.V. Villigst Link
3. Friedrich-Ebert-Stiftung Link
4. Friedrich-Naumann-Stiftung für die Freiheit Link
5. Hanns-Seidel-Stiftung Link
6. Hans-Böckler-Stiftung Link
7. Heinrich-Böll-Stiftung Link
8. Konrad-Adenauer-Stiftung e.V. Link
9. Rosa-Luxemburg-Stiftung Link
10. Stiftung der Deutschen Wirtschaft Link
11. Studienstiftung des deutschen Volkes e.V. Link
12. Ernst Ludwig Ehrlich Studienwerk Link
13. Studien Stiftung Saar Link

You can find more information on these scholarships here.

Which scholarship could I get ?

With the help of databanks for scholarship, you can find one that fits you personnaly.

For instance, with:

MyStipendium.de
Stipendienlotse.de
e-fellows.net

The Aufstiegsstipendium

The advancement scholarship supports people with professional experience in pursuing their first academic university degree.

The scholarship is a program for the promotion of gifted students and supports people who have demonstrated their special talent and commitment in their training and career. The SBB – Stiftung Begabtenförderung berufliche Bildung (Foundation for the Promotion of the Gifted in Vocational Education and Training) carries out the selection of scholarship holders on behalf of and with funds from the Federal Ministry of Education and Research and accompanies them during their studies.

You can get more info here.

Scholarships for international students

DAAD is, as far as I know, the biggest allocator of scholarships. You’ll find the database here.