In my collection is a Magic card printed in a language other than English. How can I determine which card this is?
If you can scan or photograph the card, another easy way of identifying the card is to submit it to Google Image Search (click the camera). This will find pages about that card, and these will surely tell you its name. (In fact, you might very well get the card's Gatherer page.)
Otherwise, determining to which set it belongs would greatly narrow down the search space. For at least 15 years, Wizards has been placing a set icon on the card. Wizard maintains a list of the icons for the proper sets, but this doesn't include the special sets (e.g. duel decks). A quick search reveals that TCGPlayer maintains a comprehensive list. If you have a card that predates the set icon, this earlier post will allow you to determine the set to which it belongs.
Armed with the set, obtain the card number from the small print at the bottom of the card. Locate the set (in the appropriate language) on this page and locate the card by its number.
If the number is illegible, you can still easy locate the card by looking at all the cards in the set with the correct casting cost.
This approach may fail for promo cards. If this is what you have, the copyright date can help you narrow down the search.
If all else fail, please provide a scan of the image.