Oh my goodness! The easiest way to start is to say that I follow the Associated Press Stylebook rules as learned at my Father's knee and therein after followed in the various editions of the Stylebok itself. The AP says "Periods always go inside quotation marks." Then the book says to "see quotaion marks...and that entry goes on for two pages covering more variations than at present I want to type in here !However one general rule is that if you are quoting someone the punctuation that goes with what you are quoting goes inside the quotes. (Whew!)
Commas -- the commas in a series are used to separate elements but are not used before the conjunction. Example is "I have oranges, apples and pears." If you used a comma before the conjunction "and" then you are using what is called The Oxford Comma according to that peerless userof the King's English, Inspector Morse. Should you, for some insane reason, want a copy of the Stylebook, contact your local Associated Press office or write to HQ at :
Stylebook, AP Newsfeatures
50 Rockefeller Plaza
New York, NY 10020
The last time I ordered one it was $8.75 per copy for non-members . It is cheaper for AP member newspapers, broadcast members and journalism departments and book stores serving AP member schools. Best to inquire. On the desk of any editor it is well worn and used. The book includes An A to Z list of guides to capitalization, abbreviation, punctuation, spelling, numerals and usage. Also guides and style for business and sports, a guide to punctuation and to computer terms and a bibliography. There is a basic libel manual. Also it has a guide for writing and submiting photos and photo captions and, finally, how to file a story on the wire. My latest copy is 1988. I must get a new one. With the Stylebook you are on the way to writing so that any newspaper editor will be delighted to see your copy. The delight in reading it will be relative to accuracy and content. Is this more than you wanted to know? Aloha, WOW