Active Merchant plugin is what you will want to use. Ryan Bates did a few RailsCasts on the topic http://railscasts.com/
PeepCode also has an informative Active Merchant pdf you can purchase http://peepcode.com/products/activemerchant-pdf
If you need more than that just Google Active Merchant.
BTW. Stating in a forum that "I am expecting fast reply.." will probably just piss people off and cause them to not reply and help you. It isn't proper forum etiquette.