Bartleby
Bartleby.com: Elementary Rules of Usage
Passage from William Strunk's "Elements of Style" explains how the placement of a participial phrase determines if it refers to the subject of the sentence. Examples.
Other
Punctuation Mark Rules: The Colon
A fairly comprehensive look at the uses and misuses of the grammatical element "the colon" in English punctuation. Includes information and several examples.
Other
Sandhills Community College: The Colon
A brief lesson on the uses of the colon in English punctuation. Includes examples and links for further information.