What to Know: Just about anything of interest is now inventoried online. Be sure to spell the author’s name correctly — or, if there are variant spellings (for example, Tolstoy/Tolstoi), use keywords from the title (“War,” “Peace”) and the name of the publishing house, if you know it. To find additional information that might help with a search, Kirsten Berg, a used-book buyer for Powell’s Books, in Portland, Oregon, uses the WorldCat database, which contains bibliographic records contributed by more than 50,000 libraries. Available through most libraries, WorldCat is generally free for library members.

Where to Go: Abebooks (www.abebooks.com) is an online clearinghouse for thousands of book dealers, including Powell’s, that allows you to search for new, used, rare, and out-of-print books at participating stores for free. You can also sign up for free automatic notification if the title or edition that you’re searching for is found.