That's a very hard thing to do. And not to be Mrs.Negative but please do not get their hopes up. Now that we got that out of the way try looking around and see what's going like you upcoming auditions, modeling ect? Also get them involved in a Drama Club and try to find a talent agent. Have them audition for comericals....can they sing or dance? If not find someone to help them out in that...just call around and see what's what and who's going to be there.
Well, I too have always dreamed of that. If you want the GOOD paying roles, you sign them up on Fame street or I believe (not completely sure) Star's suite. You will need to pay to get the auditions though. Or you can start a little show of your own and either take it to a director or post them on YouTube!
Yeah. And I want to be Pope when I grow up but my wife won't let me.
If they're really interested in acting, get them involved in school plays and when older, community theater. The experience and exposure will either add to their interest and enthusiasm or they'll gain a major dose of reality. While you can and should set their expectations on reality, let them live their dreams while possible. You never want to be the one they'll blame for standing in the way.