Off you are talking about running on a track, bmwcca Boston chapter is an excellent place to start. They maker you take a day of advanced driving skills first, them you can join then on track, say art nhms.
There's a North east track day listing on this Forum under track/racing/auto cross.
I will try to go a few times with comscc and scda1 this season
2008 135i | Dinan Stg 2 | APEX Arc8 | 255/235 RS3s | Vorshlag camber (-2.5) | Eibach Pro | Koni Yellows | E92 M3 arb | M3 front bits | Stoptech Street Perf pads | Droid TrackMaster for lap timing & Torque for OBD data