One piece of advice...don't always count on the forecast. If you have time, go check it to see for yourself and get wet!
Surf Conditions and Forecasting Resources:
Pretty much the "go-to" site is Surfline.com. They have comprehensive forecasting models for most major spots around the world. They also have a good surf cam network. But remember, even if Surfline says it's flat, it may not be flat.
Go to Surfline.com
LA County Lifeguards have good cams for checking the surf at Zuma and Venice Beach. This is the best cam for Zuma.
Check the Zuma Beach Surf Cam
For LA surfers, the best cam on Sunset is from SunsetSurf.com. I also really like their Malibu Surfrider cam. Not a great site for the forecast.
Go to Sunsetsurf.com
The most accurate wind and weather forecast we've found to be is Weather.com. Use the hour-by-hour to see when the wind will be switching.
Go to Weather.com
For checking swell direction and biggest spots, use the CDIP diagram. This is also a great visual to help understand where different swells will focus their energy.
Check the CDIP Southern California Swell Model

Magic Seaweed is good too, but they are focused more on Europe.
Go to MagicSeaweed.com
Surf Spots and Travel:
To get info on surf spots around the world -- WannaSurf has decent, but not complete, info on various spots around the world. A fun place to dream of all the great surf spots to go to or if you are looking to find out about surf spots in a certain area or region.
Go to WannaSurf.com
Surf Travel Company that has a lot of options all around the world.
Go to Waterwaystravel.com
For vacation rental houses at surf spots around the world.
Go to Solikai.com
For all sorts of surf travel options.
Go to SurferLiving.com
For daily shots on the surf in Nicaragua. Fun place to dream of warm, tropical barrels. Aaahhhh...
Daily Surf Shots in Nicaragua