The Spring 2010 League Rules are posted in the 2010-2011 NorCal Premier Soccer League Team Handbook. You can access the Team Handbook by clicking on the Spring League U10-13 web page then clicking on the left side menu 'NorCal Team Handbook'.

Just as a clarification (Spring 2010 age groups):

U10 play 8x8 and 30 minute halves.
U11 play 11x11 and 30 minutes halves.
U12 play 11x11 and 35 minute halves.
U13 play 11x11 and 35 minute halves.