One of the best things about ESP8266 ESP-01 WiFi modules is that they can be programmed
using popular and well known Arduino IDE and act as stand alone board with WiFi
capabilities. Thanks to ESP8266 group process of integrating ESP8266 and Arduino IDE
is pretty simple.

First step is to add http://arduino.esp8266.com/stable/package_esp8266com_index.json to Additional Boards Manager URLs in Configuration in Arduino IDE.

Then, open Boards Manager, find esp8266 and install it.

Locate and select Generic ESP8266 Module in Boards menu.

To actually program the board you will still need a small "programming" helper I've described few months ago.

  1. Connect ESP-01 into the "programmer"
  2. Connect USB-to-Serial converter to the "programmer" (you need 3.3V logic converter, 5V logic module will damage the board)
  3. Connect power
  4. Select COM port
  5. Hit "Upload" button and that's all... minute later sketch would be uploaded into ESP8266