I should also add that if you have a ESP8266-01 you can use this adapter http://www.dx.com/p/esp8266-serial-wi-fi-wireless-esp-01-adapter-module-3-3v-5v-compatible-for-arduino-403053
or you can use this module. http://www.dx.com/p/esp-07-esp8266-serial-wi-f-wireless-module-w-built-in-antenna-compatible-with-3-3v-5v-for-arduino-400559
These modules have the 5V/3.3 regulator/level converter built in.
You need need a FTDI cable/adapter like https://www.sparkfun.com/products/12977 to program. I’ll post a diagram on how to wire later to the DealXtreme source adapter.
BLACK <-> GND
RED <-> Vcc (5V)
LIGHT GREEN <-> TX
YELLOW <-> RX
GREEN <-> Not Connected
BROWN <-> Not Connected