Do not use a colon to introduce a bulleted (or numbered) list if it separates an item in the introductory sentence from its complement. "The ground rules are:" is wrong. You could say, "The ground rules are" or "The ground rules are as follows:" or "The ground rules follow."
If the list is introduced by a sentence that gets completed by the list, use commas (or semicolons) within the list, and DO end with a period or other appropriate ending punctuation.
The style of bulleted lists depends to some extent on the style of the document. In general, Sentences are given normal punctuation. Only items that are complete sentences should begin with a capital letter. Full paragraphs may wrap to the left margin; words, phrases, and sentences should be block indented unless space is a problem.
Bulleted lists may be set off from the surrounding text by additional space above and below the list. Line spacing between each bulleted item depends on the style of the document.
Phrases or mixed phrases and sentences:
List of phrases that together could be read as a complete sentence: (therefore the list requires sentence-style punctuation, in this case, commas, and a period at the end.)
See also "lists, numbered or lettered."