The official website where you can find out more about the Raspberry Pi and have a look through their Quick Start Guide.
Here you can buy your Raspberry Pi and there's a huge community of users.
3) A realistic and fairly neutral viewpoint
4) A success story in school
Swallow Hill Community School have already taken the brave step towards Innovation / early adoption
Ok, it was meant to be five, but there's a few blogs worth reading:
<UPDATE> Speech regognition on Raspi!: http://www.aonsquared.co.uk/raspi_voice_control
Another school success story : http://gotofdn.org/blog/gototech-the-goto-foundations-first-event/
Crust ->Pi tastes better with a crust.