The most typical things are...

Name: United States of Touchurselfistan or Kingdom of Harry etc

Area: This could be a map, and probably should be in a fantasy world. Some maps are sections off so you just choose a section. Some people will just describe the area they mean. In a real world based RP you can just describe your borders by what real world nations or places are included in yours.

History: The nation equivalent of a Bio. I've always felt like this is the really important want since this is where you find out if the person apply understands what they are RPing, and it's the first time you get to see their writing ability in action.

...now, personally I don't think anything else is needed. Some people will put things like military strength or population on there, but honestly I've rarely seen that amount to much. I'm more into the "Less is more" rule.

To give you an example, here is the sheet for Precipice of War.

[quote]APPLICATION

This application format is for those looking to play as a nation or an sub-national organization/NGO (just flip "nation" for "Organization" to set aside that section of the app for the name/title).

Nation:
Leader:
History: (Four-five paragraphs if not more, otherwise I may not pay attention.)[/quote]