Hi, Here's some basics about how an application can look like
Name, character name, age;
Important stats, spec, gear (armory);
Former guild(s);
Professions;
Experience from former raids;
Playtime (When you can raid);
A little more information about yourself.
Don't even bother applying if you're not:
...Mature enough for the job;
...Level 70;
...English speaking/writing;
...Capable of raiding according to our raid schedule;
...Horde. (duh?)
Remember, A application that contain a lot of important points is very much appreciated.