"Many destinations. One path." -The Avian's creed
The Aviana Sodality (commonly referred to as "Avians") is a scholarly, fraternal order. They take the mantle of the demigoddess Aviana as their own, the messenger raven of Elune, who ascended to godhood by her very wisdom. The Order itself traces a fuzzy ancestry to Aviana's druidic followers, the Druids of the Talon, but after the Third War, became a very distinguishable entity with the inclusion of the Night Elves' new allies among its membership.
Though the earliest Avians did worship Aviana as a true goddess (and indeed, a small traditionalist portion still does), they have steadily grown more secularized over time, particularly following the Third War. These days the Raven serves as an icon, more than a goddess, as a goal to be achieved and honored. The demigod who achieved ascension through knowledge and wisdom, not by divine birth like Cenarius. Her status is one, in theory, that could be mimicked. And though ascension is perhaps a lofty goal, many members do seek some kind of an enlightenment, salvation, or repentance through learning.
Avians do not distinguish, with very, very few exceptions, between "good knowledge" and "bad knowledge". All information is deemed worthy, or at the least, desirable to have. Instead the Avians see the application of knowledge as the difference between good and evil. For this reason Avians distinguish between knowledge and wisdom. Due to this, the Avians accept members of all studies and professions. They embrace combat skills, anatomy, and arcane philosophy alongside the more traditional history, art, and cultural studies. A warlock is just as welcome as a druid, what matters to the order is the nature of their morals.
Along with seeking knowledge, Avians have grown to see themselves as "protectors" of knowledge. They will try to lift the veil of ignorance where they can. This can be accomplished by teaching others, but at the same time, keeping it out of "untrustworthy" hands, and the Avians have a sort of enforcement arm for these tasks, made up of more roguish personalities.
Though the Avians are of a neutral persuasion as a society, this doesn't mean there's no wiggle room for a change in policy. In fact there are plenty of conflicting interests within the order. Any group that claims to want "all knowledge" must recognize that differeng viewpoints are needed for such objectivity. There are paladins who want to use their newfound wisdom to help others and lift the poor from the gutters and into the Light. There are rogues whose only concern is how their knowledge can lead to higher profits. And there are warlocks who want to use their wisdom to "take over" and "run society right". These differing viewpoints are always at odds within the organization, and even encouraged by the higher ups, because change is generally seen as a good thing, as without change, one cannot evolve. So these disparate forces play tug of war, sometimes they win, sometimes they lose, but they are still united by their need for information.
Execution of story in-game
The Sodality is first and foremost a roleplaying guild, with PvE tendencies. As the storyline mentions, they perform two tasks, accquisition and protection of "knowedge" (which is just about...anything).
The accquisition is played out in two steps. Characters can go about their lives, and "learn" things (such as "Hey, I heard a rumor there's Defias in Westfall". This is the first step. The second step, is sharing. This is what most guild events are for, discussion, sharing, and debate of these things, and what to do about them (like, "Oh, maybe we should go to Westfall and investigate?")
This leads to "protection". The decision to root out the Defias, who are using their knowledge of machines and subtlety to ruin the lives of others.
Of course, all this is (honestly), an elaborate justification for the guild's light, story-guided PvE prospects. All the hype and shadowy-pomp and circumstance is just a way to hopefully make it more entertaining for the members, and the way this is done is totally up to the players in question, what's laid out here is like the pirate's code: More of guidelines, than actual rules. If it's not fun in practice, why would you be expected to perform it exactly?
The Aviana Sodality also takes it's "ending ignorance" manifesto to the roleplaying sphere. It actively encourages and recruits first time roleplayers, transfers from standard realms who wish to start roleplaying but are unsure or feel uncomfortable striking out on their own. As such the environment in /guild is enforced to be mindful of this fact, and your questions can be answered.
And, as per usual, roleplayers have an open-door recruitment policy. Recruitment can be conducted in-character or out of character, as per member preference.