Reference material for the lessons will be mentioned in the lessons. For the first topic Git you must familiarize yourselves with the terminal program for your platform. We recommend following videos for
Those videos must be seen before the first lesson. Exercise while you watch them. They cover some very general computer skills. The Git subject also has some recommended videos. See them before the first lesson. They add up to about one hour.
The definitive book about Git is [Cha14]. It is free, use it.