You let me know how to study
这是想说明他教会你学习的技能还是学习什么知识?
我觉得这样表达更好：You coached me to improve my learning skill.
If you tell me the more for studying,the higher store I will get.
You are my good friend.And you are my teacher,too.
我觉得这样表达更好：You are not only my good friend but also my teacher.