Richard Ellman wrote a meticulous biography of Wilde, which is really rather interesting. As people have said, Wilde's only novel is Dorian Gray (which is, incidentally, both brilliant and enormous fun), but there are also lots of short stories, poetry, and of course the plays. I'm not sure quite how you'd classify The Critic as Artist (dialogue?) or The Soul of Man Under Socialism (essay?). Many of the short stories are rather whimsical and are apparently aimed at children, but they're still worth reading, especially (I think) Lord Arthur Savile's Crime. I adore Wilde, but much of his poetry is rather tedious and you can see all too clearly the influence of Bosie. Of the plays, I think The Importance of Being Earnest is easily the best, and the best representation of Wilde's ability. Salome is also quite interesting, but the only English translation seems to be Bosie's horrifically inaccurate one.