Hardware & Peripherals:
Hardware - detailed information about the Raspberry Pi boards.
Hardware History - guide to the Raspberry Pi models.
Low-level Peripherals - using the GPIO and other connectors.
Expansion Boards - GPIO plug-in boards providing additional functionality.
Screens - attaching a screen to the Raspberry Pi.
Cases - lots of nice cases to protect the Raspberry Pi.
Other Peripherals - all sorts of peripherals used with the Raspberry Pi.
Raspberry Pi 1st Production Board
- Announced: Yet to be! (as of 30th Jan 2012)
- Credit-card Format
- Initial 10k Batch (All Model-B's) Manufactured in China (Jan/Feb 2012)
- Should look identical to the Raspberry Pi Beta Board below (except GPIO header will not be populated).
- Nokia/Qt Development group has donated vouchers for 400 RPi units for developers
Raspberry Pi Beta Production Board
- Announced: December 2011
- Credit-Card Format
- Manufactured in UK
- Produced 100 PCBs
- Characteristic feature of hand-modded correction to PCB 
- See the blog post which includes a video explaining how the production units will differ from the beta boards.
- Pre-production board (beta board) PCB, topside
- Pre-production board (beta board) PCB, underside
- Pre-production board vs credit-card
10 of the completed Model-B boards were auctioned on eBay (Started on 1st Jan 2012) )
Raspberry Pi Alpha Board
- Announced: August 2011
- Large Format for debugging (Model-B)
- Populated with headers for GPIO, JTAG, DSI, CSI, as well as switches and LEDs for I/O testing.
Raspberry Pi USB Prototype Board
- Announced: May 2011
- The "Computer On A USB Stick" Format
- Included built-in camera
- HDMI one end and single USB the other
- Introduced the RPi Foundation to the world (any earlier links appreciated), featured by BBC Online Video.
Raspberry Pi Concept 2006 edition
- Vero-board Prototype & PCB Version
- Atmel ATmega644 microcontroller clocked at 22.1MHz
- BBC iClick's Peter Price asks whether a £15 computer can solve the programming gap (6 minutes, 3 June 2011)
- Raspberry Pi's David Braben talks to BBC's Rory Cellan-Jones (2:28 minutes, 5 May 2011)
- Raspberry Pi community tutorials on YouTube
- Podcast of a phone interview with Eben about the project and the motivations behind it (15 minutes long.) (3 June 2011) Transcription here.