A verbal commitment can be made at anytime. All this does is stop the recruiting process for the player.
The specifics have already been agreed upon and will be official in Novemeber when the two parties sign. Do not hesitate to ask for the specifics in a letter so there will be no misunderstanding later on.
Many people claim that you should not trust any coach until the day you sign. I disagree, coaches have reputations to uphold. This should be part of your homework, as to the reputation of the coach. I have found more players to change their minds than coaches during this time.