Users with 15 reputation points are told that they can flag posts. This is great, and is a big part of helping the community moderate their sites.
However, some people have noticed that some users don't realize that their flags go anywhere, and need be taught about flag responses. One place that they might be told about their flagging history is on the page where they're told that they have the privilege to flag -- last time I checked (just now), there was no mention of that history on the privilege page.
Best thing (I think) would be to include a direct link to that users flag-history page, but it would also be good just to mention it, possibly with a screenshot of someone's profile page with a mouse hovering over the link to the flag history.