ESP8266 Thing Development Board Hookup Guide
jimblom 
Setting Up Arduino
There are a variety of development environments that can be equipped to program the ESP8266. You can go with a simple Notepad/gcc setup, fine-tune an Eclipse environment, or use a virtual machine provided by Espressif. If you're just getting started, though, we recommend the comfy confines of the Arduino IDE.
Installing the Addon With the Arduino Boards Manager
With the release of Arduino 1.6.4, adding third party boards to the Arduino IDE is easily achieved through the board manager. If you're running an older version of Arduino (1.6.3 or earlier), we recommend upgrading now. As always, you can download the latest version of Arduino from arduino.cc.
To begin, you'll need to point the Arduino IDE board manager to a custom URL. Open up Arduino, then go to the Preferences (File > Preferences). Then, towards the bottom of the window, paste this URL into the "Additional Board Manager URLs" text box:
http://arduino.esp8266.com/stable/package_esp8266com_index.json
You can add multiple URLs by clicking the window icon, and pasting in one URL per line.
Hit OK. Then navigate to the Board Manager by going to Tools > Boards > Boards Manager. Look for esp8266. Click on that entry, then select Install.
The board definitions and tools for the ESP8266 include a whole new set of gcc, g++, and other reasonably large, compiled binaries, so it may take a few minutes to download and install (the archived file is ~110MB). Once the installation has completed, an Arduino-blue "INSTALLED" will appear next to the entry.
Selecting the ESP8266 Thing Board
With the Board addon installed, all that's left to do is select "SparkFun ESP8266 Thing Dev" from the Tools > Boards menu.
Then select your FTDI's port number under the Tools > Port menu.