VPN with IPSec

Dear All,

I m completely new in mikrotk era, Please help me I have 30 sites nation wide and all sites connect through VPN with head office, Meanwhile i have an linksys vpn concentrator installed and configured in Head Office and all sites have linksys bfsx041, Same thing i want in Mikrotik, the only difference is i want to change linksys concentrator in head office with mikrotik. So please tell me how i can do this or how i configured mikrotik.

Best Regards.

Hammad