I feel embarrassed to ask this. And I wish there was a less prominent place to do it. But the search button didn't help me, so I'm stuck with opening a thread..

I own my N900 for two days now. And I can, for the love of it, not figure out how to change my ringtone. Neither for Phone, for skype or for sms.
Can somebody please explain it to me and end my embarrassment?

Thank you..