An overview of academia in Germany is available from the European University Institute: Academic Careers Observatory (ACO). The ACO facilitates the flow of knowledge among researchers about national academic careers and research opportunities in the social sciences and humanitis, throughout Europe and beyond. The pages on German higher education and academic career progression are informative.
Vacancies for researchers throughout Europe, along with individual country portals and practical information is available through the researcher's portal of EURAXESS. This is written in English and is easily searchable by country, discipline, and level of experience.
German universities are normally strongly research-oritneted and typically offer a wide range of subjects. Some universities specialise in particular fields (eg. technology, art, or medicine). Universities in Germany also include a number of religious and philosophical-theological institutions. A searchable database of the 300 or so HE institutions in Germany is on the Higher Education Compass.
Permanent academic positions are rare for new academics in Germany. Typically tenure is not achieved before an academic is 42 years old and short term contracts often of 6 years is normal at the start of your career. Vacancy sites posting HE jobs in Germany include: