One of the ways nmap makes this super easy is that it prints out the submission page and asks you to submit the fingerprints if it does not know about the device:)

If you get a new device run a full scan against the device; all ports, OS detection and full service version scan.

Here is the page if you are curious:

http://nmap.org/submit/

I assume you're talking about a scan using "-O"? For example "nmap -O 192.168.0.1".

  # nmap -v -v -Pn -O -sV --version-all -p 1-65535 -oA output 192.168.0.1

The above would be great. All 65535 ports is probably overkill. But if its your device and you have the time why not? Rinse and repeat with UDP if you are feeling especially charitable.