Most people just use bullet points, I think. Typical basics to include are your name or handle, whether you're of age, notes about your writing style (such as whether you prefer past or present tense, post length, etc.), and any contact info you feel like sharing.
You can also put stuff about your past RP experiences, what general kinds of RP you're looking for (genres, celeb vs. fiction, het vs. slash, etc.), your timezone/hours you're usually on -- basically anything you think people should know up front.