hi Dipankarsaha i hope that now you find solution and if this is true i thank allah(god) , but i will writing that may be help you or other one.
iam not very old in this field but i have some knowledge:
you have to know first what SOA is ? there are many different definitions for it depending on what is your field. you have to know them. after you specify your fild you can read books about SOA in that field go to libarary.nu register to it and search for SOA you will find many many books also Mr.erl is famous one in SOA has website(www.thomaserl.com) iside it there are numbers of website also you can review them. also i recommand book called service oriented architecture for dummies.
if you have any question( or any other one) you are welcome . ihope that i can help you