What do you mean by "article"? Do you mean a short reading (like a newspaper article) or words like "a/an/the"?
If you mean a newspaper article, I don't quite know what you mean by rules for translation. I will tell you that prepositions and articles (on, of, in, with, the, a, etc.) are NOT capitalized (unless they are the first word in the title). All other words have the first letter as a capital letter (in general -- someone correct me if I'm forgetting a part of speech).
Hope this helps.