Surfrider Foundation is dedicated to protecting the oceans, and is worth checking out even if you don't live near the coast.
CapeMayWildlife.com is an awesome site put together by Mike Crewe that covers the plants of Cape May County as well as many of the animals.
If you enjoy reading about nature in New Jersey and beyond, you should really check out Joe Smith's website.
Of course, the Cape May Bird Observatory, The Nature Center of Cape May and The Wetlands Institute are always worth checking out .
Learn about some of the awesome research being done by our neighbors at Cellular Tracking Technologies.
The Lady Bird Johnson Wildflower Center's native plant database is a great tool. It allows you to search for plants by physical characteristics, light & soil requirements, native range, and more.
The Biota of North America Program (BONAP) has a terrific number of range maps for most species of vascular flora that occur in the U.S.
The Native Plant Society of New Jersey provides a lot of information with a local focus, including some great nature walks and festivals to check out.
The Missouri Botanical Garden website has a lot of great information on native plants, including how to garden uses for hundreds of species.