The bboard basically serves as the KGB's mailing list. Freshmen don't know how to access it. Freshmen also don't know how to access the wiki, but in case you somehow accessed the wiki and do not know how to access the bboard here is how:
0: Log into yo' andrew webmail: https://webmail.andrew.cmu.edu/
1: Click the "folders" link at the top of yo' page.
2: See the whole "Unsubscribe/Subscribe" block? Type "assocs.kgb" and then his "subscribe".
3: You now have access to the bboard.