in my yishivah (a branch of chofets chaim) i know that at least one high school rebbe was available to talk to about these inyanim. the rosh hayishiva brought it up with my in my end of the year meeting after 2nd year. (unfortunately i didnt take the opportunity to actually get the help i needed than). there is a rebbe who gives parenting classes in kollel who advises bringing up the topic at the beginning of puberty in a fyi way of what will happen and that this is normal. this also keeps the channel of comunication open if the boy wants to discuss more.

Thats probably a good idea. I think its officially "recommended" (as in what gedolim have done) to have a brief talk about these stuff when the kid is about 15/16 but I think most of us get hit with desires earlier and should get some sort of notice early like you said 

he was talking about 7-10 years old