New Handbook for European Studies Librarians

 University of Minnesota Libraries has published a free Handbook for European Studies Librarians (in e-book or PDF formats).

It has many subsections devoted to specific areas (e.g. "Iberian Studies") and topics (e.g. "Russian Federation: LGBTQIA+ Studies Resources").

Chapter 26 is devoted to European Legal Research:

"Researching the law of any European jurisdiction is often a multi-step process; librarians must first look to the domestic law of the individual jurisdiction, then determine what-if any-impact supranational organizations will have on the analysis. This chapter introduces librarians to the basics of European Union (EU) legal research, and briefly considers the impact of Council of Europe treaties in domestic human rights research. The second half of the chapter provides general guidance on researching the domestic law of a common law or civil law jurisdiction, focusing on how and where to find the law (whether statutes or codes) and cases, generally within the context of the civil versus common law distinction."