How I can make calls with the Arduino Mega ADK ?

Well, first all you have a good day.

I need to do a project in which I have to use the Arduino Mega ADK to communicate it with a cell phone that has Android and then make a call or send a message. (if they be both better).
The truth is I don´t where to start, I´m new to Arduino and Android, but if someone could guide me (any tutorial related to the subject, information, or whatever that can help me) I would be grateful.

In advance thank you and I hope you have a nice day.

You can send sms and make your android speak text using Bluetooth arduino pi formerly known as btinterface. You can also use processing which is in buggy. or app inventor.