Sorry to hear about your sons injury. My son also tore his labrum but in his non throwing arm. Its quite a recovery process. There is a good post by Tequilla about labrum surgery, give it a read, he details the process well.
Also, for post surgery...make sure you get the ice machine!! Its not always given or sometimes its an option you need to purchase. I cant recommend this enough. Its critical for post surgery comfort and will enable your son to take less meds.