Scientific Beekeeping: My go-to source for real-world advice:
A fellow beekeeper that I work with has formulated a brood disease formula that is easy to use and could save an unhealthy hive. Take a look:
Bee Informed: Great source for beekeeping practices
The Honeybee Conservancy: Great source for plantings and other resources
Empire State Honey Producers Association, Inc.
NY Bee Wellness Workshops: Working for the health of bees