According to the plagiarism tutorial, the following is true:
a) you don't have to cite famous proverbs because they're common knowledge.
b) when you summarize a block of text from another work, citing the source at the end of your paper is sufficient.
c) if you quote your roommate in an interview, you don't have to cite him/her or use quotation marks.
d) you don't have to use quotation marks when you quote an author as long as you cite the author's name at the end of the paragraph.