Looking recently at the always interesting and useful Arachnoid web site, I came across a guide that P. Lutus has written for the N810 that is likely useful for the N800 as well. It is called "Hacking the Nokia N810" and can be found at http://arachnoid.com/linux/nokia/index.html. He covers using SSH, connecting with a cell phone, bluetooth, clock syncronization, use of bluetooth, the usb interface, wi-fi configuration, root access and comments on the gps of the 810.

It is worth a look.

It's worth noting that a lot of this information is out of date (particularly the section on root access).