Hawaii has some great surfing spots because of the swells that roll in from the Pacific Ocean. These spots are scattered across hundreds of beaches all over the state of Hawaii. You could literally spend a year surfing these beaches and never have to surf the same spot twice.
The biggest waves in Hawaii are located on the North Shore of the islands. Waves during the winter are typically bigger than the waves during the rest of the year. The island of Oahu is home to some of the world's largest waves. The north shore of Oahu awesome of the best surfers in the world and hosts big surfing competitions. Waimea Bay Beach Park draws huge crowds of people there to watch the big wave riders. It's pretty typical to drive down the main highway and see several photographers just waiting to capture the big one.
These waters have swells that reach to be over thirty feet. Winter winds prevent this from being a swimming beach during these months. The waves pound the beach with a force so hard that it can be heard for miles. The summer months, however, bring a totally different Waimea. The water is usually calm enough for swimmers June through September. Sunset Beach is also another popular winter surfing destination for the same reasons as above ... big waves. Don't forget about the world famous Banzai Pipeline located at Ehukai Beach. The pipeline attracts world famous surfers to these incredible long tube waves. Be careful, here the water is extremely shallow and these great waves break over top of a coral reef. This can make for treacherous wipeouts. This is not the place for beginners.
Wakiki beach is also another world famous surfing destination, but for much different reasons. Wakiki has long predictable waves that are not nearly as tall or as threatening as their northern counterparts. Wakiki is a great place for beginner surfers. You can walk up the beach and find tons of different places to take a lesson.
Honolua Bay on Maui is also a popular surfing spot for the experienced surfer. There are lots of great beaches as well as surfing spots in Maui. Lahaina is a great spot for beginners and there are a couple of different surfing schools located here. It is also a popular destination for wind surfing and kite surfing because of the strong winds on Maui. Maui even has its very own kite beach. On any given day you can drive by a see the shoreline full of kite boarders, some of whom you 'd probably recognize from the magazines.
Hanalei Bay located on the North shore of Kauai also has some great waves. The bay itself is crescent shaped and the waves here are also going to be the biggest during the winter months. The bay makes for some great snorkeling during the summer months.
There are also some great spots to surf and the islands of Hawaii as well as Molokai, they are just not as famous of some of these others. Whatever island you pick you can't go wrong surfing in Hawaii.