Statutes are second only to the Constitution as a source of law.
Federal legislation is officially published in the Federal Law Gazette Bundesgesetzblatt (BGBL in citations): Teil I has domestic laws, Teil II has international agreements which have been ratified by Germany.
Fundstellennachweis A is the annual index for BGBL I
The LawBod has the print volumes at German 010 1949
Sammlung des Bundesrechts : Bundesgesetzblatt, Teil III at German 030 B942 (a consolidation made in 1963) is useful if you are looking for legislation passed between 1867-1958.
Collections of federal laws at German.KV15
Deutsche Gesetze : Sammlung des Zivil-, Straf- und Verfahrensrechts also known simply as Schönfelder
Verfassungs- und Verwaltungsgesetze der Bundesrepublik Deutschland : Textausgabe also known as Sartorius
Codes and subject based collections of laws are published in form of a Kommentar: a section by section explanation of the legislation, drawing together academic commentary and judicial decisions which have discussed the law. It is usual for the section of the law under examination to be reproduced first.
The websites of the various Federal Ministeries often maintain freely accessible collections of legislation within their remit. (See example below from BMAS)
German publishers produce Kommentare for each code (and, indeed, other subject-collections of legislation).
Nebengesetze (amendments) are officially published in the Budlesgesetsblatt, and picked up by the Kommentare.
A long code can be divided into two parts the Allgemeiner Teil (principles behind the code, general rules) and Besonderer Teil (details and particular rules)
Zustimmungsgesetz: proposed act which requires approval by the Bundesrat.
Rechtsverordnungen (regulations made by executive or administrative authorities)
Verwaltungsakt (VA) is an administrative act or order.
Remember an English translation is never an authoritative version of the code - but can be used as a crib, a first step towards comprehension.
Always check the date of the translation - it may be recording an historic version of the act, not its current state.
In addition to a short title, codes and acts have an official abbreviation (Abkürzung) making citations neat - if not necessarily comprehensible for the novice.
The first division is the Artikel.
German citation practice often uses a symbol § rather than Art. (§§ for articles).
The divisions of an Artikel are paragraphs Absatz or Abs., which, in turn, can be divided into clauses Satz or S. However, the use of these abbreviations seems to be optional.
Common practice is to give the title of the law in abbreviated form, date, citation to page (S) in Bundesgesetzblatt (BGBl. I)
The link below should help you discover both the abbreviation in use and the title for current German legislation.
Pinpoint references - down to sentence level - can be made within legislation.