Hi, yeah, that's it, the dreaded puberty for boys. It may not progress rapidly, because he's just had a huge growth spurt by the sounds of what you've said. But with my DS (now 12 and a man cub) I first noticed genital growth and a few pubic hairs. Of course the smell. Genitals now adult size I think and lots of pubic hair. Hairs under arms are coming in now, and leg hair, and his voice has broken I think. Sometimes I call him and he responds and I think -'who let Brian Blessed in?'
I expect you'll get a bit of moodiness. And then the inevitable nocturnal emission. DS in his innocence shared that with me (!!!!!!!!) which led to me having the conversation about ejaculation and masturbation etc. (Where is this boy's father when the chips are down?) My husband bought him a book, as his contribution, although I'm not sure DS is that into it, as I suspect he googled everything he needed to know. Book looks OK and was highly recommended according to DH:Puberty Boy, by Geoff Price (nice manly name there), published by Allen & Unwin.
Apparently minerals like zinc make a big difference to pubescent children's moodswings, so you might google that too.
And if course I guess there will be the inevitable interest in the gender of choice. You may never know any of this, I guess.
Smell re room, I agree, it's a kind of old sock funk. So a nice effective gut gentle shower gel and definitely a shower/bath every day. Because they stink. I was teased dreadfully at school because I smelt (first time I have ever told any one that) so I was determined Ds wouldn't smell and if he did not to make him feel embarrassed at all. he couldn't care less and there appears to be a kind of kudos in stinking.
Spots will come eventually. Ds uses Simple facial wash, gentle so as not to strip the skin. Get him into having his own special cosmetics, maybe, so above all he doesn't find it a negative experience or an embarrassing one.
Facial hair comes much later i think.
Hope all goes well for your DS.
Oh, finally, I think the growth spurt can be physically exhausting so plenty of sleep is essential if you can manage that.