Bruce Waltke is an OT scholar who has been studying Proverbs for decades. His two–volume commentary on Proverbs in the NICOT series is outstanding, and he coauthored the notes on Proverbs in the NIV Zondervan Study Bible.

You can listen to Waltke lecture for 26 hours on Proverbs for free via BiblicalTraining.org. I listened to his lectures recently, and they are thoughtful and edifying.