Of the three pairs of legs on the honeybee, the hind legs are the most specialized. The bee's various jointed appendages combine to collect the pollen that has been deposited in hairs throughout the body. The pollen is then deposited into the pollen basket. From time to time the bee will use mouth secretions to moisten the pollen and keep it together as well as attached to hairs in the basket.

The nectar of a flower, while rich in carbohydrates is an extremely poor source of protein. Pollen however has a high protein component and along with 10 of the essential amino acids needed for growth. "Bee bread" is a mixture of pollen and honey. This is what most of the developing larvae and the adult bees will eat. To produce a new queen a worker egg is deposited in a larger chamber. The larvae is fed "royal jelly" which is composed of gland secretions from the workers mixed with "bee bread" that has a higher percentage of carbohydrates.

Reference

The Bumblebee Pages: An excellent source of information about the Honeybees close relative the Bumblebee.