Leadership, magical prowess, vitality, mastery, insight, divine illumination, protection from outside evil forces from all directions, grounded energy, fulfillment of potential, inspiration, longevity, personal happiness, greatly increased riches, infinite wisdom, luminous beauty, majesty, indomitable spirit and strength, invisibility, power of transformation and metaphysical knowledge.
as mentioned, it's believed Dragon Magick was founded by D.J. Conway [not a great source of knowledge to say the least] but like Wicca, it has evolved and has become very personal and spiritual. dragons are astral beings who practitioners can call upon for guidance and strength [much the same way a spirit guide or deity would] http://www.fox-moon.com/dragon.html is one of the best [and most common] sources to learn from. most information is verbally passed down through clans from dragons, and very little is written down, let alone shared outside the clan. i also wrote an article on some basics called 'Dragon Magick' and can be found in the Spell Casters rituals.
in terms of dragonology you're going to have to do a lot of research. dragons can be found all over the world. many don't appear like the typical european dragon, some [like the lindworm] don't have wings, or only 2 legs, some have feathers, wings, but no legs. it's long and complicated, but basically every culture has a dragon myth. for this reason some belief dragons were physical [like dinosaurs] but died out a few centuries ago. others believe they were physical but traveled to the astral. then there's those who think it's just some great story telling. research and choose for yourself.