They say you're only as good as your reputation . . . but who is "they"?
Any decent claim requires that someone stand behind it—preferably a well-respected source from an equally well-respected institution. You may not know the reputation of the scientist or institution involved, but chances are you can find out.
Once you figure out who did the research and where, you can go further by finding where the research was originally published. Most respected scientific journals are peer-reviewed, which means that other scientists read the articles vying for publication and screen out any shoddy science.
Beware science stories that go directly to mainstream media, also known as “science by press release.” This can be a ploy to circumvent the peer-review process. Notorious examples include a 1989 press conference announcing successful cold fusion and a 2002 press conference announcing successful human cloning. Both stories were later debunked.
Last but not least, it never hurts to find out who paid for the research. Research funded by sources with vested interests (drug companies and advocacy groups, for example) should be given extra scrutiny. Some manufacturers publicize the positive aspects of their product while burying any research that doesn't support their desired outcome.
You can see a list of peer-reviewed journals at http://www.eurekalert.org/links.php?jrnl=A.