<font color=navy>As Lap3 said, Orange County & Long Beach are closer to DL, but LAX typically has better deals because it's a bigger airport.
Orange County is the closest. Take 5 south to 55 west, and 405 south to get to the airport.
Long Beach is next - Take 5 south to 22 west, to 405 north to get to Long Beach.
To get to LAX you take the 5 north to the 91 west, 605 north, to the 105 west -- that's the fastest way to get to LAX. You can also take 5 north to 91 west to 110 north to 105 west. Orrr, you can take 5 north to 91 west to 405 north, and get off on Century Blvd (follow the signs).
(I live about 15 minutes from LAX, towards DL, so I drive those freeways all the time)