Welcome to Gaia! ::

well, dragons come in many forms, and depending on the form they have different abbilities and personalities.

ill start with the basics:
the basic terrain groupings of dragons:
forest
mountain
prairie
arctic
desert
jungle

each of these terrains have their own dragon or dragons.

Forest:
Knuckers
marsupials

Mountain:
european
asian
tibetan

prairie:
amphithere
lindworm

arctic:
frost

desert:
wyvern

jungle:
mexican amphithere

here is a basic description of each of these dragons:

Knucker:
4 legs, vestigial wings
found in damp woods near rabbits and other smaller prey. they cannot fly, though they have tiny wings. their nest is usually a small well, deep pomd or their own made hole by water. they grow about 30 ft long, and upto 6 ft tall. their skin is a leathery brown, dull red, or greenish blue. they have a venomous bite and also use constriction. they eat rabbits, deer, farm animals, and sometimes stray children.

marsupial:
4 legs, wings, fiery pouch
largely confined to southern australia. it breathes blue smoke, and uses fires to catch its prey. its home is in the blue mountain eucalyptus forests. it grows about 25 ft long and 18 ft high. it can be green or blue, and uses flame breath, "boxing", and kicking feet for weapons. it eats any large marsupials, and smaller prey is caught when it has young.

europian:
4 legs, full wings, dark color
very good as using language, and known for its fire and love for treasure. it lives in a mountain or sea cave in a remote area. they get 45 ft long and 17 ft high. they can be red, green, black, or gold. they can use flames, claws, and horns for attacking. they eat cattle, sheep, and humans (if there is no choice)

asian lung:
4 legs, no wings, mane
often found near lakes, streams, or rivers that hide their homes. the number of toes on each claw depends on the sub species. they live in an underwater cave or grotto. and they grow to 40 ft long and 15 ft high. they can be blue, black, white, red or yellow. they attack using horns, teeth, and claws but only for defense. they eat birds, fish and swans particularly.

tibetan:
4 legs, no wings
thinner and redder than the asian lung. lover of high altitudes. its home is in an open mountainside durring the summer, and a shallow den in the winter. they grow to be 40ft long and 12 ft high. they are only red in color. they can bite or constrict for attacking. they eat mainly yetis and sometimes yaks.

amphithere:
no legs, mothlike wings
they live amond the reeds on lakes or offshore islands. they can grow 45 ft long and 10 ft high. they are green and yellow in color. they can use flame, tail lash, and constriction as attacks. they eat all the larger mamals of north america.

lindworm:
2 legs, no wings
their nests are shallow nest in the earth, out of the reach of the wind. they grow to be 35 ft long and 10 ft high. they are usually green, pale orange, or yellow. they use claws and constriction, and they eat camels.

frost:
4 legs, full wings, light color
frost dragons migrate from pole to pole every year to ensure their favored climates. they usually live in caves hollowed from a glacier or iceberg. they can grow 40 ft long and 15 feet high. they are pure white, or white tinged with blue or pink. they have a frost breath, tail, claws and horns to attack. they eat giant squid, polar bears, orcas, and leapord seals.

wyvern:
2 legs, full wings
this is the largest dragon known. it usually lives in rocky crags or sand dunes. they grow 50 ft long, and 20 ft high. they are muddy brown to lime green in color. they attack with teeth, claws, tail and dropping from great hights. they primarilly eat elephants, but also hippos, rhinos, or other large herbavore.

mexican amphithere:
similar to the regular amphithere only it lives in southern north america and all of south america.

Please keep in mind that this is a very basic description of all the dragons known, and that i would add more if i had the time, or if i thought you would be at all interested. please msg me if you have any questions.

(edited past this point)

i would like to add on some basic information that i remembered i should put on here.

some ages of dragons:
chinese: unknown
European: 300 years
Amphithere: 250 years
Knucker: 120 years

it takes 36 months for the basic dragon egg to fully develop and hatch.

to produce flame, the dragon has a flamable venom that is produced by glands in their heads. when this venom is sparked using their spark puch it ignites and produces flame.

dragon bones are hollow and lightweigt like birds, though they are much stronger.

a dragon can spot gems from 6k ft.

dragons have a basic alphabet of runes, though it only be known to dragons and those who have befriended them.

dragons can speak any language they care to learn, though many dragons cannot speak due to stubborness.

if very fortunate, a human can befriend a dragon and sometimes even be allowed to fly with the dragon. if a dragon is mad with you, you better run, or offer it a large gem or some meat.

dragon dung can be used to scare off animals of a dangerous nature.

dragon teeth can make some of the most sharp and durable weapons and tools.

dragon scales can be processed in a way that allowes them to be an invisable ink that glows under a full moon.

dragons blood, in small amounts, can be used to heal wounds. though if you use too much it can burn through your skin.

treated dragon hide can be used on the wings of gliders to improve weight and aerodynamics.

dragon dust can be used in many ways, like pacifying fully grown dragons.

pretty much my whole life has been devoted to studying them, so i should know

actually no the dragonology books are not incorect, except for a few small points. i actually have a college major in dragonology, which branched off of cryptozoology. the earnest books are acually one of the best referances around.

they come in different shapes and sizes and not all of them fly.

I went to wikipedia for alot of information. Like did you know that in Revelation 12:3, an enormous red beast with seven heads is described, whose tail sweeps one third of the stars from heaven down to earth(held to be symbolic of the fall of angels)?