Cameron Diaz has reportedly asked Nicole Richie to plan her wedding.

The 'Other Woman' actress, who recently sparked rumours she is engaged to former Good Charlotte rocker Benji Madden rocker after being spotted showing off a new diamond ring at various events in Los Angeles, has turned to his stylist sister-in-law for advice.

A source told US OK! magazine: ''Cam has never been a big fan of weddings, so she has no idea where to start.''

The 42-year-old actress and Nicole, who have been friends for years, have been scouting Napa Valley in northern California for the perfect venue, as she hopes to tie the knot next spring.

Nicole, 33, recently revealed she takes full ''responsibility'' for Benji and Cameron getting together.

The 32-year-old socialite - who is married to Benji's twin brother Joel Madden - ''approves'' of the couple's relationship and admitted she was the one who got them together.

Asked if she set them up, she previously said: ''Yes. I'm going to take responsibility for everything!''