First, check one of the many reputable lyrics sites online that have specific lyrics-search functions built in.
An example of a lyrics-search engine is: http://www.songlyrics.com/search.php, a commercial website that has a high Google page rank for the keywords "song lyrics."
If you know any other information about the song, such as the artist or album name, try searching with those key words as well.
If lyrics websites are not helpful for you, try the search tips below. They are designed to help you find your song title and improve your online search skills for any type of information you may need.
It is best to know as many of the lyrics as possible. The more lyrics you know, the better your search parameters will be.
If you have a recording or clip of the song, play it and jot down the lyrics accurately.
Generally, for popular songs, there is a "catchy tune" to the song called the "chorus" that is repeated multiple times, characterized by a strong melody and easy-to-remember lyrics.
The lyrics to the chorus are, in many instances, either the title itself, included in the title, or related to the title of the song.
Search with this phrase first, using quote marks around the phrase when you type it into a search engine, adding the word "lyrics" before it and the phrase "song title" after it. Your search string should look like this:
lyrics "insert common lyrics to the chorus part of the song here" song title
This will command the search engine, such as Google, Yahoo!, or MS Live Search, to return pages that contain those words. The quote marks around the lyrics command search engines to keep the format and structure of those words, without switching the words around when it is matching content on target pages.
Adding the word "lyrics" as your first word in the search string instructs the search engine to give priority to web pages that have the word "lyrics" as an important element. You also want the word "song title" in the search string for the same reason.
Play around with other combinations of your search string based on the above logic.
If you cannot find the results you want, it may be because the lyrics you are using are too common.
Make note of the unique words or phrases used in your song lyrics and choose a portion that is not commonly shared with other songs for your search parameters. For example, "I love you" and "I miss you" are common to so many songs that using these phrases will not yield very specific results.
You might have to switch your search string around and test different combinations before you see relevant search results.
Try searching with longer phrases. The more information you give to the search engine, the more likely you will get a matching result.
When searching with a very long portion of lyrics, however, you can remove the quote marks.
If you still cannot find the song title, start posting questions online. Take advantage of the forum or community functions of song lyrics or music sharing websites that are most related to your song, making sure you are asking questions in the right place. Don't be afraid to let people help you.