a colon
A colon is used before a quote when the quote is introduced by a complete sentence. In this case, "The newsletter provided necessary information" is a complete sentence. It contains both a subject (newsletter) and verb (provided) without any other parts of speech that might necessitate more information.
A comma is used before a quotation when the information preceding the quote is an introductory phrase and not a complete sentence.
A semicolon and a period should NEVER be used before a quotation. These two punctuation marks separate the quote from it's introductory or explanatory information too much and leave the quote floating in the sentence without any original writing to attach it to the rest of the piece.