Punctuation colons, quite different from the colon found on the end of your intestines, is used when giving lists, quotes, or delivering appositives. It has been said that the colon is a promise, and whatever comes after the colon is the delivering of the promise. I sometimes have a problem with colons since I can't always decide to use a colon, or just commas. Colons should never separate verbs from their objects as doing this will cause the reader much confusion. A nice little web page for several examples of colons can be found on the picture of the colon.
