Hire an attorney who is well-versed in tort law. The best way to gather evidence is to be aware of everything that should be presented to the judge or magistrate hearing your case. Preparation is key to a successful result.
Get All of the Facts and Evidence Ready
Gather all information that either supports the allegation of libel (that is, information that proves the statements are false) or information that directly supports the libelous written content and pull it all together.
Make sure You Have the Content Available
Have the copy as it appeared in print in whatever media it appeared and all of the media in which it appeared. An in situ copy (just as it appeared in the media in which it appeared) of the alleged written statement or statements at issue. The basics of a libel case are showing that an injury to reputation has occurred by providing the written or recorded content.
Show your Damages
Contact witnesses who support your position and have them ready to appear in court, if necessary. This is especially true if the statements made were to a small group of people, as opposed to the public as a whole. You must also show hoe you were damaged, whether personal or business reputation, business or personal monetary loss or other compensable (usually monetary) loss directly related to the written content.