I've been riding for years on pavement with an original Trek 520 Sport-Touring bicycle with standard size (29-inch) wheels. I would like to start riding "off road" and am looking for a suitable mountain bike.
By "off road", I mean off pavement but still remaining on established dirt, gravel or cinder roads, jeep trails, or established bicycle trails. Nothing cross-country or extreme riding for me.
On a mountain bike, what are the pros and cons of 26-inch versus 29-inch wheels, especially in lieu of the type of riding I am contemplating?