There is a law called “Berufsqualifikationsfeststellungsgesetz” (BQFG) where the acknowledgement of skills is regulated, as far es the federal level is concerned. You have the right, that your certificates from another country is checked, whether it is equal to a German certificate. This does not depend on your national status. There are non-regulated professions where you do not need a certificate. It is highly advisable to present your certificates, so the future employer can judge your professional abilities more adequately. For the regulated-professions, you need the acknowledgement of your skills, these are especially jobs in the health and educational system.
Whether you need an acknowledgement or not can be seen at the website www.anerkennung-in-deutschland.de. There you can find out, where you can get detailed information for your profession. There is also a hotline in German and English: + 49 30 1815 -1111.
The acknowledgement procedure will take place in the federal state you are living in, but you can make an application in advance, while still being in another country. You need certified true copies of your certificates and an officially certified translation. There is a database of certified translators at www.justizdolmetscher.de . Your documents may be certified at the residents registration office or at church institutions.
For more information, see: http://www.bamf.de/SharedDocs/Anlagen/DE/Publikationen/Broschueren/willkommen-in-deutschland.pdf?__blob=publicationFile Page 37