As shown by the red lines in the image below, each row of holes on either side of the slot in the middle of the breadboard have electrical connection with each other (and not to any other row, including those across the central slot):
Each row has the electrical connection, I just didn't feel like drawing a zillion lines.
but I'm not sure when the power rails are....can you please tell me where I should put the GND and VCC in?
You can use any row you like as rails (just don't use one row for both rails!).
(Do the parts that stick out on the side have anything to do with the placement of power rails?)
No. The only purpose of those is to allow you to interlock multiple breadboards together (but only in a mechanical manner, not electrical).