Okay, here's a basic skeleton for you guys. Add any sections you feel might be missing

Chosen of: Air, Water, Earth, Fire, Man
Name: Try to fit within the universe's naming conventions.
Gender:
Age: Anywhere from 20 to 40.
Role: In the [url=http://tvtropes.org/pmwiki/pmwiki.php/Main/FiveManBand]group[/url]. Again, the Chosen of Water will end up as the leader.
Element: Some notes about bending (Which may be subject to change depending on Book 3's results) --
[list]
[*]For the Chosen of Fire, Combustionbending and Lightningbending are mutually exclusive: if you choose one, you cannot have the other. [mostlyjoking]And if you're a Combustionbender, you have to be the tallest of the group.[/mostlyjoking][/*]
[*]The Chosen of Earth may not know lavabending.[/*]
[*]If the Chosen of Air is a formalized Airbending Master without mastering the thirty-six tiers of airbending, then they must describe the technique they created to ascend to the rank. They should also have a Sky Bison in their care.[/*]
[*]Bloodbending is...something to be resolved privately between the Chosen of Water and myself if the player so chooses to have this skill.[/*]
[/list]
Animal Companion: If your character has one, with a series-shared limited of two [url=http://tvtropes.org/pmwiki/pmwiki.php/Main/TeamPet]Team Pets[/url] for the whole group.
Appearance: Height, weight, eye color, hair color, scars, missing/replaced limbs, clothes, etc. If an image fits, link it.
Equipment: Any weapons, trinkets, nifty toys, etc. that the character carries with them. Personal vehicles would also go here. 
[*]The Chosen of Man may not have guns to begin with.[/*]
Personality: Detail is a must here...
Bio: ...and here.

If some of you guys want your characters to be relatives, friends, rivals, etc. with each other, then work on that together and put that in the Bio section.

Also, some more stuff you guys can factor into your history:

Korra disappears ten years after the series ends. The world searches for her for over a year until all but her friends and the Order of the White Lotus have given up the search. The Order of the White Lotus then begin looking for (ultimately) good-hearted bending experts (and one good-hearted non-bending expert) to do the Avatar's job while she remains missing. Five years after Korra has gone missing, all five of the Chosen have been found and accepted the Order's proposal to meet at Republic City when they are called to be given a mission of the utmost importance, which happens to be acting as the five Chosen. None of the Chosen have any idea what they're being called to do. All they know is that the Order of the White Lotus will one day call them to take on a very important mission. So your character could be waiting anywhere from one day to about four years before they're called to Republic City.

And again, don't forget about this [url=http://www.roleplayerguild.com/topics/50446/posts/ooc?page=1#post-1549355]post[/url].