I second on Aaron Stevenson's Cornerspeed
program. I did the level 1 school past summer and a track day on the season-closing Grand Course layout at VIR. I have been posting good stuff about this organization here more than once, and I don't want to sound like an insider, which I am not, but Aaron's dedication to promote the sport of motorcycle racing is something to look up to. His programs are well run and very safe. Everyone know that if they pull a stunt that puts other people in danger, they are off the track for the rest of the day. A beginner myself, on a dual-sport bike (Tiger 06), I was quite thankful to those experienced buffs that flew by me only in a safe place and manner.
Then, the other Aaron's program Cornerspin
was the school that gave me the biggest boost in my motorcycling skills. The idea of riding 7 hp little dirtbikes around on hard-packed slippery tracks may sound un-sexy, but it's the best way to learn what impact the use (and misuse) of weight placement, throttle and brake control really have on your bike. Immediate feedback is delivered by many wipeouts. I stopped counting how many times I crashed. I posted a detailed account earlier here
Just this past Sat-Sunday (9-10 Feb) Cornerspin held a graduate riding day and I was back, for mere $135 a day including the bike, all day of valuable lessons that'll definitely prevent some ugly crashes with a 500lbs 100hp beheamoth later on.