Hi Sunil,
Following document provide in-depth idea of promotion management as its a detailed user guide (including your open questions), please refer to it thoroughly (page no. 32 onwards):
http://help.sap.com/businessobject/product_guides/boexir4/en/xi4_lcm_user_en.pdf
If you are looking very intutive step-by-step guide for each and every option then its not available.
If you are following all the steps of above guide and still promotion of content is not working then I would strongly suggest to raise a case with SAP support as they will be able to connect to your environment to rectify exact issue.