Intro to Bee Biology for Beekeepers

Here's a handy reference about the different bees in a hive, and how the population within the hive fluctuates throughout the year:

Basic Bee Biology for Beekeepers

Some of the major biological features that beekeepers need to understand are: basic bee nest ecology, the bee caste system, bee anatomy, the development of bee brood, worker bee sequence of duties, caste brood rearing/adult population seasonality, communication as a "key" to maintaining the social cohesion of the colony, queen and colony reproduction/replacement, and how to read/understand bee behavior/biology.