What’s it going to be like well there's a question with a 1000 answer I'm afraid,
he will change during it, that’s a certain, it’s a hard course to do,
expect him to become a bit more ladish,and independent,
but there will be times where he will want to quit and give it all up, trust me every one has this feeling,
and your job is just to listen and be his shoulder to cry on,
I did my basic ages ago (01) now and have since left (07) and joined the stabs (TA so be gentle) I've done 1 tour and about to do another soon, hence why I’m on RP getting some girls point of view on keeping in touch whilst I am away, feel free to add any suggestions on it

But any questions I'll be happy todo my best,
But in short it really depends on him, how he copes with the massive change, how well he does and his troop during training, I had a really good troop so it was nice and easy in comparison to my mates troop who I swear had the special needs class with him poor bastard lol