I don't understand what the I2C is, and where to find? 
http://img821.imageshack.us/img821/7520/uitleg.jpg
I placed 1 resistor, but I don't understand where to put the other one.
As I found some information over the web and the things you said, I've made a circuit as I think it should be, but it is partly made with some imagination (a)
I don't know if it is good, or bad. (The red square is the accelerometer)
The picture of the circuit is in the link:
http://img692.imageshack.us/img692/1576/schemas.jpg
Thanks for your quick feedback!