I can assure you there is very little "official-ness" in the kin, we are pretty laid back and casual actually.
Yes you sign up at the web site and then copy the recruitment template and paste it into a new post in our recruitment section.
We have no real requirements, you must have at least one character at level 20 or above, the only other requirement is that you conduct yourself in a respectful manner to other kin members and to the wider game community at all times.
We have over 300 members, with people at almost every level and play-style imaginable. We generally raid twice a week and run instances on a regular basis, but there is no requirement what so ever to join in.
Things have been a little quiet lately (the pre-expansion lull I think), but we still have at least 20 people logged on most nights, many more than that on weekends.
So if your interested and think you'd be a good fit for us then by all means sign up and apply