Regarding Adjectives
For clarity, separate two or more adjectives with commas if each modifies the noun alone. (Kavic is a fantastic, faithful dog.) (It is going to be a long, hot summer.)
Regarding Other Punctuation
When the context calls for a comma at the end of material enclosed in quotation marks, parentheses, or brackets, the comma should be placed inside the quotation marks but outside the parentheses or brackets. (Bill replied, “Yes,” when asked if he’d like to go.) (Bill’s comment, though stilted (and somewhat inflammatory), was still taken to heart.)
A good rule of thumb is to let your ear be the guide. Read your sentences aloud. You will naturally pause in those places that need a comma.