It's been said often that any piece of information is only six degrees of separation away from the one who wants to know it. (Even a current film exploits this premise.) Of course, that doesn't mean that only six inquiries will turn up the information; it means that only six queries--down the right path--will turn it up. Thus, you must prod a good many spokes of the wheel to find the right path. 
Some writers think that only nonfiction writers need to research. That's not so. Even fiction and poetry writers need to clarify and specify. When you're casting your net, use every resource you can possibly think of, particularly for "odd" information. Most writers will automatically think of the library, but it's surprising how many don't. If your own library-research and then the help of the librarian fail to turn up the information, ask for suggestions. You may be referred to experts known to the librarian (teachers, religious leaders, politically connected people, etc). Your own friends may know the right person for you to talk to. 

Among common resources, depending on what it is you want to know, are numerous institutions and their staffs: 
 

aquariums
arboretums 
associations 
colleges 
foreign embassies 
government offices 
historial societies 
historical sites
hospitals 
libraries 
museums 
organizations with "causes" 
planetariums 
professional organizations 
tourist offices 
zoos

Don't overlook the vast databases available through computer networks. If you need a degree of linkage with any of these, it's time to get friendly with a reference librarian or computer-savvy friend. 

Your friends may be more helpful than you thought by what you know about them. You can't know all their links. Talk about your project and what you're looking for. Sometimes the most unlikely-seeming source will lead to your information. It's called "networking." 

Pass the word and someone will know someone, who knows someone, who knows someone, who knows someone, who knows. 

You're only One Degree away from Friends 

Many writers don't like to talk about the specifics of their projects (aside from possible interaction with other writers in a workshop setting). Some feel that to "talk it out" takes away the impetus to write it. You have to know how you feel and work, and judge just how much you want to talk about a manuscript-in-progress. 

But for both nonfiction and fiction, you can make good use of your friends' knowledge for settings with which they are familiar. If you're not sure the name of a character is "right" for an area, time, ethnic culture, or for any other reason, the people who care about you, and therefore your work, are often remarkably helpful. 

Friends are often valuable resources for brainstorming titles. If they're clever people, you may well find that some casual conversation may spark just the right combination of words to fulfill your needs. 

Reach out beyond the files of your own mind. Someone you know knows something you want to know.