Puberty in Boys

My son is in 6th grade now and he's not adjusting well to the changes - having to switch classes.  With the start of school, he also only sees his dad on weekends now. I am married but Monday - Friday, I am SINGLE MOM because of dad's work. 

My son and I dipped our toes into the "puberty" talk a couple weeks ago, but that's all we did.  He doesn't want to talk to mom about that!  We talked about body hair (he thinks it's cool that his toes are "getting furry") and I told him he could get acne in other places than his face (back, chest, neck acne). I remember my brother always grossing us out by popping pimples on his chest in front of us. Gross. I need to either read up more on what he needs to know or make dad sit down and start the talk with him on a weekend.

Dad has never potty trained any of the six kids, had "the talk", or anything else like that so it'll probably come back to me to deal with this too.  If you can't tell, I'm feeling a bit resentful at the moment.  Not a good place to be.