ESP8266 12e Arduino IDE outputs garbage values on serial monitor

The baud rate you specify in your program and the baud rate in the serial monitor must match. The ESP8266 outputs a boot message at its own baud rate (varies from model to model - try 57600) before it executes your sketch.

For example:

You can choose any (within reason) baud rate in your program as long as you also choose the same baud rate in whatever is communicating with it (such as the serial monitor in the IDE). If you want to see the boot messages then the serial monitor will have to be set to the right baud rate.