The BLEFriend board is designed to be easy to use and get started with.
In most circumstance, the only thing you'll need is an FTDI driver, and a terminal emulator to start working with BLE from your development machine.
This guide will explain some of the different operating modes that the BLEFriend board can be configure to operate in, how to setup your terminal emulator to start talking to the BLEFriend, and a basic example of sending bi-directional data between the BLEFriend and a BLE-enabled phone or tablet.
The BLEFriend is (of course) capable of much more than basic UART data exchanges! You can use it to create custom GATT services and characteristics. You can emulate a Beacon for indoor navigation purposes. You can update the firmware on your device over the air, or even develop your own firmware thanks to the SWD pins on the bottom of the PCB if you possess a HW debugger like the Segger J-Link.
Depending on the version of the board you have or whether or not you have access to a J-Link, you can even use the BLEFriend as a powerful Bluetooth Low Energy sniffer to debug or reverse engineer existing BLE devices, and write your own custom applications or drivers for existing HW!
Have a look through this quick start guide to familiarise yourself with the basics, though, and you should be able to quickly move on to more advanced topics in no time!