The best thing to do is take the Grand Los Angeles/Stars' Homes Tour with Starline Tour Group. Their drivers, David ("Pappy") and Brian were very knowledgeable and entertaining. We were allowed off at all of the most important attractions, so we could enjoy the sights close up. Even after the tour, Brian helped suggest places to eat, sights left to see, and where "not to stray" after dark.
One of our most memorable moments was meeting Sidney Poitier in person at the airport. He was just picking up his luggage at the same carousel that we were. He was very nice, shook our hands, and wished us well, after signing his autograph. Also Venice Beach was very entertaining, Santa Monica food was great, and the scenery in Malibu is to die for.
Quick Tips:
I suggest eating at Micelli's Restaurant in Hollywood. It's a wonderful Italian Restaurant with singing waiters.
Best Way To Get Around: