Hi there !
In this article, we'll discuss about the famous Raspberry Pi, a tiny and cheap computer. You can get one for around $30 and it has a credit card size. The whole thing is run by a 700MHz ARM-based SoC ,assisted by 256MB of RAM (512MB on recent models), 2 USB ports, an ethernet port, both HDMI and composite video output and a SDcard slot where you basically put your OS. It's powered via a micro-USB input (5V @~700mA).
When you receive your Pi, first thing that comes in mind is "gosh it's tiny !". Indeed, this credit card size is quite astonishing for a computer, even if you are used to deal with Arduino and other PCBs of the same size. Fact is that you have here a fully capable computer on which you can put a Linux distribution, decode 1080p videos and run "reasonably powerful" programs. Let's try this little piece of silicon.
Basically, all the information you'll need are gathered here : http://www.raspberrypi.org/. You'll only need a SD card (4go is fine, 8Go is good), and an other computer with a SD card slot to burn your OS.
First thing to do is to download the burner : Win32 Disk Imager. Then download an OS that is compatible with your Raspberry. I strongly encourage you to choose Raspbian “wheezy” if you never experienced Raspberry before. It's a Linux OS based on the Debian distribution.
Then you'll have to burn this. Open Win3D Disk Imager, select your distribution, and write it to the SD card. The process can take several minutes. When it's done, just insert it into your Rasp slot, and it should do the trick.
To start using your Pi without a display, you can use putty and SSH to remotely take control over your Rasp. All you have to do is connect your Rasp to your local network, download PuTTY and connect to the default name of the Raspberry : raspberrypi (or its IP address).
If you see (after a possible warning message ) a console that invites you to enter a login, your Raspberry is OK and connected ! If not, check again if you're connected to the network.
Enter the default user : "pi" with password "raspberry" (without double quotes). You'll have a prompt that indicates you are now able to type commands over your raspberry. Before doing anything, type the following command :
Select expand_rootfs so your raspberry will use your whole SD card memory. You can also overclock it up to 1000Mhz (I did it without a problem). Reboot your raspberry as asked.
Now, want to see more ? You can use a protocol named VNC that allows you to launch a desktop interface on your Raspberry over the network. Reconnect to your Pi and use this command to download a vnc server :
sudo apt-get install tightvncserver
then launch a server with the command
You'll be prompt to enter a password.
If you're on Windows, download VNC Viewer. Once you get it, launch it and select as VNC server "raspberrypi:1". Then hit the connect button and see the magic!
From now on, you are able to remotely use your Raspberry and start thinking about all the applications it has! For example, you can use it as a file server by installing a samba server (which is really easy), as a media center with the well known XBMC... This is totally up to you!