How important do you imagine research to be? I know how important I feel it is. Very. I know some people, who will remain nameless, who believe that research is a waste of time for short story writing or fantasy novels. There is nothing farther from the truth.
Recently I wrote a short story for a competition. It had to be based on the Titanic. I wanted my work to look professional. I wanted it to be flawless. I spent several hours one night over Christmas break just reading information about the Titanic. By the time I was done with the research I was able to sit down and write my entire story in a single sitting. It actually made the writing easier since I knew more than enough details about the Titanic and its crew. Also, for once in a rare time, I was satisfied with my work.
By common sense research is necessary for things like Magazine article writing, modern or historical based novels, and research papers (duh!) But the one fact that must never be overlooked in research's necessity in fantasy writing.
Research for fantasy writing often takes a different twist than research for the things I've listed above. In fact it even defies the common conception of research.
Fantasy research involves studying people, which is fun, analyzing their conversations, developing characters from their faults, all that fun stuff. Fantasy must have believable characters that the reader can attach to. This is achieved by the research into real people.
Fantasy research also involves studying the world around you. The fantasy writer needs to be able to describe new things straight from his imagination. Thus the fantasy writer needs to study their surrounding and be able to describe them. How else, if the writer cannot do that, can the writer describe something no one has ever seen before?
Finally, fantasy research involves bookstores. Find out what has been written before. Know what fantasy ideas are original. People always enjoy a fresh, brand new fantasy. Also find out what trends are selling. I am not advising you to write a Twilight novel, but you can create something original along the same line of a selling book trend. It just takes some work and some research.