You also need a mini USB cable (type-A to mini type-B): the kind you would connect to a USB mobile hard disk, for example.
2. Download the Arduino environment
To program the Seeeduino board you need the Arduino environment.
Download: the latest version from the download page: http://arduino.cc/en/Main/Software
When the download finishes, unzip the downloaded file. Make sure to preserve the folder structure. Double-click the folder to open it. There should be a few files and sub-folders inside.
3. Locate the USB drivers
You will need to install the drivers for the FTDI chip on the board. These can be found in the drivers/FTDI USB Drivers directory of the Arduino distribution. In the next step ("Connect the board"), you will point Window's Add New Hardware wizard to these drivers.
The latest version of the drivers can be found on the FTDI website: http://www.ftdichip.com/Drivers/VCP.htm
4. Connect the board
On the Seeeduino, the power source is selected by the PWR switch between the USB and power plugs.
To power the board from the USB port (good for controlling low power devices like LEDs), toggle the switch towards the chip side. To power the board from an external power supply (6-12V), toggle the switch towards outside. Other two switches would be toggled towards chip for this startup tryout.
The power LED should be on.
The Add New Hardware wizard will open. Tell it not to connect to Windows update and click next.