This is an old thread - but I figured I'd add to it.
I like to Hotkey my town halls: I use 9 and 0 since they are right next to the "P" hotkey.
Note: Sometimes I'll use 8, 9, 0 for 3 halls.
For barracks - sometimes I'll do this and sometimes not - depends on the situation: Hotkey for ogres, normally (whatever you're comfortable with) 5,6,7,8 or whatever).