Job Seeker VISA Holder: Finding Work!

Your question is too broad to give all but the most general response!  It can really help to narrow it down by stating your qualifications and skills.

There is the official Employment Office (Arbeitsamt) that helps people with German residency. Not sure if they are allowed to help people on a job seeking visa though.

Otherwise, like everywhere in the world; newspapers and the internet.

As often gets mentioned on this site, language is critical to getting a job. Without some specifically desired skill like in some sectors of the IT field, one has little opportunity beyond sweeping floors and stocking shelves. Even being a waiter or bartender requires knowing reasonable German. Plus the country is trying to integrate and help a million refugees - so not a great time to be a foreigner looking for work unless you speak German and are in a hot job market sector.