When you say "lower Middle Ages," do you mean in the French sense of bas moyen age, ~1000-1500? (English would usually say "early" and "later" rather than high and low).

If so, you might be interested in:

• Ian Mortimer, The Time Traveller's Guide to the Fourteenth Century
• Barbara Hanawalt, The Ties That Bound: Peasant Families in Medieval England

For the early (or "high" in high/low; 500-1000CE) Middle Ages, the best book to start with is Peter Brown, The Rise of Western Christendom, but that does not really focus on peasant life really at all. Maybe Julia Smith, Europe After Rome, although Brown is the much more entertaining writer.

Chris Wickham writes a lot about peasant life in that era, but his books are SUPER dense.