Hi Satya,
Expert Dogboy have already answered your Question, Being new am not sure whether you understood fully or not.
However, being you're new to APO - We Welcome you.
Remember - Always explore yourself the SCN forum or google around to find answer yourself.
All the steps you wanted to know from SA creation --> Transferring them to APO etc are already very much available here.
Few links for your questions are below.
APO Sales Scheduling Agreement - External Procurement - SAP Library
Integration of Scheduling Agreements - Integration via APO Core Interface (CIF) - SAP Library
Transferring APO scheduling agreeement through CIF
Buckle your Shoes - Start Exploring
Just my Thoughts
Vinoth