A lot of people get confused about where and how to use the colon.
For instance, some people will place a colon after a verb to introduce things that follow, as in: "The four reasons are: greed, anger, stupidty and laziness."
However, here’s a tidy little rule to remember: Never use a colon after a verb, but do use it after a noun.
Let me rewrite the above example to show you what I mean: "The four reasons are the following: greed, anger, stupidity and laziness."
Here, even though the colon is used correctly, you now have a wordiness and awkwardiness problem.
Solution: Just take the colon out of the first sentence.
(Also, I just contradicted myself by saying never use a colon after a verb when that’s exactly what you have to use to introduce a quotation of more than one sentence. Example: He said: "Blah. Blah." Oops! Anyway, don’t use it after are or include and other verbs that are introducing a series of nouns or thoughts within a sentence.)