What level of riders are you? I recently moved away from Hawaii, but while I lived there I rode with Tradewinds cycling. They are a great group of riders, typically split in to A,B and C groups.

If you goto Oahu, get in touch with them through "The Bike Shop", the team goes for group rides every saturday and sunday. Many of them also ride together during the week.

They are all very friendly and are always glad to take visitors out on the group rides and show them the beautiful riding on the island.