Hello, Rachel,
Let's see if I'm understanding correctly: You've pulled up encyclopedias in a catalog search and want to know how to locate them? There should be a little "Availability" link under the book title and information; if you click it, it will give you the floor the item is on and the call number.
As far as knowing if it's a good resource or not, click on a promising title and scroll down the item's page to the table of contents. Hopefully there will be a complete list of chapters to see if there is a section specifically on law libraries (or potentially "special" or "private" libraries).
For more in-depth information, we carry the Law Library Journal http://unomaha.worldcat.org/oclc/50636172
Some books: Basics of Law Librarianship: http://unomaha.worldcat.org/oclc/21910392
Law librarianship in the 21st Century: http://unomaha.worldcat.org/oclc/71126716
Let me know if you need more help!
Emily M., reference associate