Are there any Linux administaration related peer-run websites out there where people could ask questions in stackoverflow fashion?
Yes, I am aware that it's not really a programming question, however I guess it would be handy to know where to go with such non-programming, but closely-related stuff.
ServerFault... so similar it's even run by the same people!
EDIT: It's out of beta now, so you don't need a special password anymore.
Yep! ServerFault is StackOverflow's sister site for system administration. It's in closed beta, but you can find the password on the StackOverflow blog.
I recall having a good experience on http://ubuntuforums.org/, if you happen to be using that distribution.