Hi,
Good question, but unfortunately I'm not aware of a specific tutorial that shows all of the steps or the entire process.
Have you read the Security section of the GP 10 help file? It appears to be pretty straightforward, albeit the discussion is in topical chunks.
It's under:
Setting up the system -> User setup -> Security
Let me know if there are specific questions that it doesn't address.
Thanks,
Steve Endow
Dynamics GP Certified Trainer
Dynamics GP Certified Professional