Bees are usually attracted to large patches (more clustered the better) of shallow flowers, where there is a nice big center of yellow pollen in the middle. They seem to be attracted more to flowers that are more white, blue, purple or in the yellow tones. But once attracted to the area, they can pollinate any source they like. Your best bet is to use native plants and wildflowers, and also to set up your yard to be an ecologically inviting pollinator habitat.
Here's a good site by the USDA to read up on how to attract garden pollinators...
http://www.fs.fed.us/wildflowers/pollinators/gardening.shtmlInfo on Bees
http://www.fs.fed.us/wildflowers/pollinators/animals/bees.shtmlA PDF on pollinators esp. for Eastern USA (Note pages 1-8 for good info on bees)
http://www.fs.fed.us/wildflowers/pollinators/documents/AttractingPollinatorsEasternUS_V1.pdfFor plants for your specific location....try Pollinator Partnership. Use your zip code to find out what your ecoregion you're in and each one has a PDF to tell you exactly what plants do best for your region. They only have info on USA and Canada regions right now, but they have some great info for each region. They even have an app for it!!
http://www.pollinator.org/guides.htmHere's a generic list of perennial plants that can work ...
clovers, larkspurs, daisies, milkweeds, passion vine, sage(salvia) plants
Lavandula spp. (Lavender),
Rosemarinus officinalis (Rosemary)
Salvia spp. (Sage)
Echinacea spp. (Coneflower)
Helianthus spp. (Sunflower)
Cercis spp. (Redbud)
Nepeta spp. (Catnip)
Penstemon spp. (Penstemon)
Stachys spp. (Lamb’s ears)
Verbena spp. (Verbena)
Phacelia spp. (Bells or Phacelia)
Aster spp. (Aster)
Rudbeckia spp. (Black-eyed Susan)
Origanum spp. (Oregano)
Achilliea millefolium (Yarrow)
etc.