Firstly: Wiping Over the Bottom of the Leather Socks
The bottom of the leather socks is not wiped over. This is the position of the Hanafis, Hanbalis, Zahiris, and a group of the Salaf. It is also the choice of Ibn al-Mundhir, Ibn Baz, and Ibn `Uthaymin.
Secondly: Repeated Wiping Over Them
It is makruh to wipe over leather socks more than once per purification. The majority  Hanafis have stated that it is not a sunnah. have explicitly mentioned this: Malikis, Shafi`is, and Hanbalis.
Thirdly: Right, Left, or Both Together
The one wiping wipes his right first then the left. This is the position of the Malikis, Shafi`is, an opinion among the Hanbalis, and the choice of Ibn Baz.