The easiest way to make fast progress is to connect with research already performed by others. When possible, such information should always be verified from original sources. To find such research, go online, go to your local LDS FHC, go to your library, and join genealogy clubs. Eventually your major information sources are likely to be German civil records and German church registers. German church records start as early as the 15th century, but for many areas extant records start only after the end of the 30 Years' War in 1648, or later.
Further documents are also available in German archives.
Examples of available documents include tax rolls, emigration papers, land registers, wills, and court cases. Most of these have not been filmed by the LDS and are available only at the appropriate archive. Catalogs of the holdings of some archives are available in printed form in some US research libraries. Keep in mind a general rule of genealogy is to go from the known to the unknown, and not the other way around. For example, if your name is Bauer, you should concentrate on expanding the tree of Bauers related to you by examining documents that refer to them.