Purchase copies of some current tabloids and study how the stories have been cobbled together. What you'll find is that these often weave in references to just enough well known facts to give the material a semblance of truth (for example, a tsunami can destroy an entire village). Many of these have their roots in urban legends (for example, giant alligators living in city sewers) and frequently incorporate icons of pop culture (for example, Michael Jackson and Bubbles). The result is something like this: "Giant Tsunami Off Santa Barbara Coast Washes Alligator Into Neverland: Michael Jackson Fears For Missing Chimp!"
Start collecting ideas that would be fun to use in your fictitious feature. Four great web sites to bookmark for this purpose are Absolutely Totally Useless, Snopes, The Dumb Network, and The Phobia List. These sources are replete with obscure information about history, scams, old wives' tales, urban myths, accounts of stupid crooks, and everything you'd ever want to know about phobias. Jot down the ones you think are the funniest along with notations on how they could be used to grab your readers' attention. Example: "Doctors Confirm George Bush Suffers From Hippopotomonstrosesquippedaliophobia." That's a real word, by the way, and has nothing to do with monster hippos. Look it up.
Plan your content just as you would a real newspaper story. Identify who, what, when, where, why, and how. Your lead sentence should be a strong hook that tells readers right from the start what this story is about. Exaggerate liberally.
Decide on the slant you want to take for your fake story. For example, it could be a series of "eyewitness" accounts of a strange and mysterious event or an interview with the actual subject of the story (for example, an exclusive chat with the representative of an alien race that wants to start a farm co-op in the Midwest).
Determine what kind of photos would make your fake story seem more convincing. Thanks to the wonders of today's photo editing software, you can tweak, morph, and manipulate perfectly normal snapshots into perfectly weird hoaxes.