I think everyone will have a different answer depending on their experiences and their responsibilities within an organisation, i.e. IT support come across and deal with different issues to teachers. It also depends on how you want to use Moodle and which features and modules you intend to use.
You could take a systematic approach and do some specific keyword searches on the Moodle.org forums in Google like this: your keyword site:http://moodle.org/mod/forum/
I hope this helps!