When we went to school we learned to capitalize the first word, last word and every important word in a title. Important words were any noun, pronoun, verb, adjective, or adverb. Words not capitalize din a title unless they were the first or last word of the title were prepositions, articles, conjunctions, and the word "to" (as in "Man Tries to Bite Dog").
That applied whether it was the title of a paper we were writing, the title of a book to which we were referring, or the title of a newspaper article. Somewhere between then and now, the rules have changed.
Both Examiner.com, Yahoo! News, and several other online news publishers prefer titles to be capitalized as if they were an ordinary sentence. They say it is easier and quicker to read. A title which, under the old scheme, would have read "Man Bites 52 Dogs, Kobayashi Wins Oscar Mayer Contest" would now read "Man bites 52 dogs, Kobayashi wins Oscar Mayer contest" for either Examiner.com or Yahoo! News. For news articles intended for publication directly on the Yahoo! Contributor Network (Y!CN), however, the first version (all important words) would apply.
In the example above proper nouns, of course, still get capitalized. Oscar Mayer is the name of a company, and Kobayashi is the name of a famous hot dog eating champion, so they both get capitalized. The sentence style capitalization rules make the headline or title easier to read.
To complicate matters even more, the publishing tool on the Y!CN platform automatically converts titles to standard capitalization even if the article is for Yahoo! News. The Examiner publishing tool gives you free rein (or free reign, if you prefer - I don't) to capitalize the title however you wish, right or wrong.
The same capitalization rules apply to stand-alone sub-headings within a news article on these platforms. That is to say that if the above article included a subsection detailing eating contest opponents who have been defeated by Kobayashi, there might be a subheading called: "Eating Champion's Previous Victims" for the Yahoo! Contributor Network or "Eating champion's previous victims" for Examiner or Yahoo! News.