The Nokia N900 RX-51 Service Manual has just made its way to the internet, making it possible for you to see how your N900 looks from the inside. The manual in addition to providing step by step instructions on how to take your N900 apart also shows an exploded view of the device, a screenshot of which is below.
The manual is for use by trained Nokia service center employees and not for the end user to learn how to reduce the N900 to pieces. I cannot stress how important it is for you to never try this yourself. That said, have fun. Download here.