sql server report scheduling jobs to run

I would like to know all the ways to scheduling standard subscription jobs to run on ssrs 2008 r2. (This would not include a .net application. This may include sql scripts that can be executed.)

 Basically I know if you look at 'SQL Server Reporting Services Site Settings', you will when jobs are scheduled to execute and/or when other jobs ran in the past.

  However, I would like to know if there is another way jobs can be scheduled and not show up on this web display?

  For example when you are on the 'Home Page' for sql server reporting services, and you click on one of the subscriptions scheduled to run and select 'processing options', you can select 'report-specific schedule' or shared schedule? Would you tell me what the difference is between these two options? Why would you 'share a schedule' and how do you setup the connection for 'sharing' the schedule?