I am a big fan of the Raspberry Pi. And I think there is no better way to learn about computers and take your knowledge to a deeper level than building your own computer. The folks at Kano must agree, because they have put together this kit than combines the Pi with everything the owner needs to build a workable and very useful computer. Now you can buy all these things separately, but this kit saves you time and makes up for any lack of knowledge you might have in this area.
You will still need to have a display device to connect to it. Preferably this will be a HDMI device, though it is possible to hook it up to a non-HDMI device. (See here for details.)
For more on the Kano, go here: Kano – Make a Computer.