The #Tor relay documentation on www.torproject.org has shown its age and some of us have been working on writing something new, currently it lives on trac but will live on a website eventually.
The Tor Relay Guide https://trac.torproject.org/projects/tor/wiki/TorRelayGuide
It also features instructions to setup automatic package updates for multiple Linux distributions.
I'd like to get your feedback! The preferred location is via email or on the trac ticket: https://trac.torproject.org/projects/tor/ticket/24497
thanks, nusenu