Santa Monica is about 30 minutes drive north of LAX. It is a huge tourist destination because it has everything you might want to see. Great shopping both luxury and mainstram, dining, many coffee houses, and a number of bars and lounges. You will also get to visit the world-famous Santa Monica Pier (appearing in hundreds of movies). It is one of the most visited areas in Los Angeles. It will take you about 30 minutes drive from the airport to SM, and another 30-45 minutes back to the airport depending on traffic. So plan accordingly.
Santa Monica 3rd street promenade is a great place to spend the day. You can also rent a bike and bike all the way south to Venice Beach.
The city offers free Wifi.
The best pizza in Santa Monica is Joe's NY pizza. Make sure to get yours before heading down to the beach.