Advice to Writers is a good source of quotes
“If you did not write every day, the poisons would accumulate and you would begin to die, or act crazy or both–you must stay drunk on writing so reality cannot destroy you” [RAY BRADBURY].
“No one says a novel has to be one thing. It can be anything it wants to be, a vaudeville show, the six o’clock news, the mumblings of wild men saddled by demons” [ISHMAEL REED].
“Any writer who has difficulty in writing is probably not onto his true subject, but wasting time with false, petty goals; as soon as you connect with your true subject you will write” [JOYCE CAROL OATES].