Solomon, the wisest man who ever lived, is usually considered to be the primary writer of Proverbs, but not the only one. Chapter 30 is attributed to Agur son of Jakeh and chapter 31 to King Lemuel. Proverbs 22:17 refers to the "sayings of the wise" and 24:23 mentions additional saying of the wise.
Based on authorship, most of the book would have come from the 10th century B.C. Proverbs 25:1 makes reference to copying proverbs in the time of king Hezekiah, so at least part of the book, probably the later portion, was copied or appended at a later time (between 715 to 686 B.C.)
Proverbs is generally uplifting, giving advice on how to live life. Whether one believes it was inspired by God or not, the proverbs can still be appreciated for their simple messages and keen insights.
Due to there being 31 chapters in Proverbs, it is a popular form of study for some devout religious people to read 1 Proverb a day, thereby going through the entire book in most months.