Hi MGEB - you'll get more responses if you post in the California forum. Also, when you ask there, give us an idea of your hotel / resort budget per night, as it will help us point you in the right direction.
In general, there are a lot of options starting in Santa Barbara and heading south from there. Ventura / Oxnard have some places. Malibu has pretty limited or very expensive options. In LA itself, there are 4 hotels in Santa Monica right on (or almost on) the sand, plus several more with ocean views. After that, there are the South Bay beach cities (Manhattan Beach, Hermosa Beach, Redondo Beach) which have options with a mix of price ranges. On the Palos Verdes Peninsula there is the Terranea Resort, which has ocean views and a small beach. After that, there are the beaches in Orange County - Newport, Huntington and Laguna Beaches - the latter has some great resorts. There's also San Clemente and Dana Point before you head south into San Diego County which I am not as familiar with in terms of what beach options are available, but there are many great areas there including La Jolla and Mission Bay, as well as Coronado.