MLK,
1. If it touches issues which he must keep (e.g. gezel) one may teach him.
2. There are situations where it is permissible to ask a goy to do something. There are also situations where it is not but one may ask a goy to ask another goy. You should ask a rav. You should also learn the halachot both tho know what you may and may not do and to know when you have a question and how to ask it.
Regarding the issue of lights, it is my understanding that you can ask him to skim through a book or magazine and tell you what he thinks. After he turns on the light for himself you can tell him not to turn it off. If the light is fluorescent it is easier as lighting it according to most opinions is d’rabbanan.