There is a huge amout of different bee web-sites. We can give merely a small sample here...
Bumble Bees   Honey Bees
 

A surprising list of bee references is given on An Updating Bibliography of the Bees of the World ...
seems that they really try to be up to date

Vladosta State University has a good bee pageThe Bees of Florida, with identification keys (down to genera)
of Apidae and Halictidae, their distribution and visited plants.
 
BUMBLE BEES
  The Natural History Museum has a good link on the bumble bees of the world, giving some information about world species, including an identification key to the British species, biogeographical information, and a great reference list.
another very good and informative site on bumble bees: basic anatomy, physiology and behaviour, a list of plants visited by bumble bees and a good reference and link - page.
   
HONEY BEES

Some basic honey bee informations can be found on http://plantphys.info/Plants_Human/bees/bees.html

Cyber Bee is quite an informative honey bee page, featuring biology, a variety of photos, research news and links to important honey bee research centers of the world.
BeeSource.com is a beekeeper's homepage. However, it provides important publications on honey bee recruitment by Adrian Wenner. Some of these articles are from journals which are difficult to access. Check them out!!!