Usually individual treads at SAAB forums, these are good write ups about different things done to SAABs:

Changing the Cabin Air Filter -step-by-step instructions, by me

Changing your oil - step-by-step with plenty of pictures, by me
Customizing the 9-3's grill - quick tutorial on how to add a custom wire mesh and remove the wing on the grill, by abdukted1456

DI Cassette Repair - how to repair a DIC with a broken peg and a missing spring, by me
DI Cassette Replacement - a quick video on how to replace the Direct Ignition (DI) cassette on SAABs
Fuel Pump - six page tutorial on repairing the fuel pump on modern SAABs

Fuel Pump - pictorial write up meant for a SAAB 9000 but on a NG900 it is pretty much the same once you drop the tank.
Installation of projector beam headlights - touche6784's very comprehensive write up on how he adapted BMW projector beams to a SAAB, with plenty of pictures

Manual transmission flushing - a good write up on how to flush a stick shift box

NG900/9-3 Fan Resistor Replacement - great write up at SAAB Wiki
SAAB Oil Change How To - if you never changed the oil by yourself you should try it: it's cheaper and gives you a sense of satisfaction. This short tutorial is a quick primer on changing your oil
TD04 turbo rebuild - step by step with pictures, hosted at TSL

Tomi Liljemark's site - has some mods for SAABs that are better left for those with a penchant for electronics