problem in home automation

im new to this site we r doing sms based home automation project ( not internet based) we have to connect GSM modem to microcontroller how to connect gsm modem to microcontroller ????

Please see the datasheet, usually GSM phones are connected to microcontroller via serial communication and AT commands are used to read and write sms to and from mobile phone.
and you can make something like reading sms which are written in a specific format
e.g. TV 1
and when you receive sms, decode it, and switch on the TV. its really simple to make. you can download AT command manual from internet.