How to create a live update policy

Hello,

I have symantec endpoint protection manager12.1.100in which i have created many groups. now i want to create a sepearate live update policy for one of the group to schedule it for getting updates on a specified time. Can you just help me out woth this??
Also, can you please let me know the difference between shared and non-shared policies ?

Regarsd,
Anish