Make it enough for us to read and sate our interest.

Editing is up to you. Don't post something with a billion errors, but we act as 3rd party editors by reading your work here, and posting our thoughts.
Anyway, to give you a better idea of how much to post... Take a shot at several hundred words. It really depends on you as a writer - if you have to force yourself to write a longer piece, then chances are you'll either a) lose interest and stop, or; b) fill it with crap.
Anyway, welcome, and have fun.