University of Calgary
University of Calgary: Parentheses and Rules for Use
This site contains information regarding the correct usage of parentheses in original material and in quoted material. Examples are included for all points discussed.
Virginia Tech
Virginia Tech: Parentheses and Rules for Use
This resource contains five rules for correctly using parentheses and a section regarding capitalization within parentheses. Examples are included for each of the rules.
University of Victoria (Canada)
The U Vic Writer's Guide: Grammar: Parentheses
This site contains information regarding the correct usage of parentheses, along with examples.