Anyone who's on any
Internet mailing list, if they're
paying attention, will quickly determine the
social order of said list.
Like in real life, a handful of people contribute most of the meaningful discourse, and are considered the experts, even the celebrities of the list. These are the people that if you ever meet them in real life you will think of them as their email address or onscreen moniker instead of their real name.
Some mailing lists are very much the jump right in kind, but most require you to lurk for a few weeks and learn the lay of the land.
Soon, you'll figure out everyone's territory and areas of expertise and will hopefully carve out your own little niche.