Stay away from any contests that automatically publish your photo but then makes you buy a book, item, or tells you to attend a conference if you give them your credit card information. The company should be buying your photograph or paying you royalities, not the other way around.

International Library of Photographers, Photography Vibe/Circle of Photographers all run these scams and make money off the innocent person just trying to enter a contest. Whenever you want to enter a contest just check Google for the name of the contest to check feedback from others.