Hi Karthik
Please check:
Help for Freshers in WF- http://scn.sap.com/community/bpm/business-workflow/blog/2011/02/15/a-little-help-for-sap-workflow-freshers-part-1
Build WF from Scratch - http://scn.sap.com/docs/DOC-3224
WF for starters-Part I http://scn.sap.com/community/bpm/business-workflow/blog/2012/05/18/workflow-recipe-for-passionate-starters--part-i-spice-up
WF for starters - Part II http://scn.sap.com/community/bpm/business-workflow/blog/2012/05/18/workflow-recipe-for-passionate-starters--part-i-spice-up
The best book ever:
www.workflowbook.com
Regards,
Modak