Can someone point me to where I should begin?
And one more question: What is the minimum amount of money needed to start?
Basically, you need to at least know some strategy, the most common is buy low sell high, sounds simple but really complicated. To learn to trade, there are free courses online, you can also find some tutorials on youtube. The trading discussion here in the forum might help.
That is all useful and definitely can help to get some insight into trading and some basic information however that will not teach him how to trade.
That takes a lot of dedication, time and hands on experience and still there is no guarantee that will make him successful trader. Trading is not for everyone.