Help with I2C Communication
The start condition is what tells the other devices to start listening.  Same thing with regular RS232.
Here is an image from a sparkfun.com  article about I2C.  As you can see the start condition is the state change of the clock and data in the beginning.  The real trick is to get the device address correct.  It is a 7 bit address left justified in the first 8 bits and bit 0 is the read/write bit.  So if the datasheet says 0x6b, then on the wires it'll look like 0xd6 or 0xd7 depending on the state of the read/write bit.



As for the data, it's the next 8+ bits.  Everything is normal there.  So you will always send at least 16 bits every time when writing, probably more because you'll probably have to specify the register within the device.  When reading, the device will take over the SDA line, after the address is sent, and send data as you clock it.