I started Ben Witherington III's Jesus the Sage.
On page 6, Witherington says that mass literacy is a modern phenomenon, for writing in the ancient world took money and leisure----both in terms of the cumbersome and expensive writing materials, and also in terms of the writing itself. Witherington states that "Surveys of as literate a culture as ancient Egypt suggest only a 1-10% degree of literacy." (Yet, see Witherington's blog posts on Jewish literacy in the time of Jesus: here, here, here, and here.) For Witherington, a significant amount of wisdom literature was produced within the royal court, for there are indications that the authors were advisers to the king, plus their agricultural references indicate an upper-class milieu. At the same time, Witherington maintains that wisdom literature could be preserving oral material from a variety of sources: "rich and poor, family, clan and court" (page 6). Witherington says that there is a lack of evidence for the existence of royal schools during Israel's monarchical period, which is when he dates Proverbs, since he does not see any exilic or post-exilic themes within it (but he dates Ecclesiastes to the Hellenistic Period, on the basis of its late Hebrew and its themes). For Witherington, when Proverbs refers to instruction from the father and the mother, it is talking about the family, not the school.
An interesting point that Witherington makes is that biblical wisdom literature such as Proverbs was seeking to provide an alternative to fertility religions. It warns about sexual immorality and it makes wisdom at most "a personification of an attribute of God or perhaps of God's creation" (as opposed to being a goddess, perhaps; page 10). (Witherington seems to presume, at least here, that sexual acts were a part of ancient fertility cults, when that is disputed by scholars, at least when it comes to Ugaritic and other ancient Near Eastern religions.) He also states that wisdom literature sought to make Yahwism applicable to Israelites' day-to-day lives, since Yahwism tended to focus largely on major events of Israel's history rather than daily life, which was more the focus of fertility cults. Although Witherington ascribes an elite milieu to wisdom literature, he also appears to believe that it was relevant to many other Israelites.